OII Oceaneering International Inc

As filed with the Securities and Exchange Commission on November 25, 2024

Registration No. 333-     

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

OCEANEERING INTERNATIONAL, INC.

(Exact name of registrant as specified in its charter)

Jennifer F. Simons

Senior Vice President, Chief Legal Officer and Secretary

5875 North Sam Houston Parkway West, Suite 400

Houston, Texas 77086

(713) 329-4500

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copy to:

Carina L. Antweil

Baker Botts L.L.P.

910 Louisiana Street

Houston, Texas 77002-4995

(713) 229-1234

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this Registration Statement.

If the only securities being registered on this Form are to be offered pursuant to dividend or interest reinvestment plans, please check the following box. ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, as amended (the “Securities Act”), other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ☑

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☑

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act:

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

Prospectus

OCEANEERING INTERNATIONAL, INC.

Senior Debt Securities

We may offer and sell from time to time in one or more offerings senior debt securities. This prospectus describes the general terms of those securities and the general manner in which we will offer them. We will provide the specific terms of the senior debt securities in one or more supplements to this prospectus. You should read this prospectus and the applicable prospectus supplement carefully before you invest in our securities. No person may use this prospectus to offer and sell our securities unless a prospectus supplement accompanies this prospectus.

Our common stock is listed on the New York Stock Exchange under the symbol “OII.”

Investing in our securities involves risks that are referenced in the “Risk Factors” section on page 1 of this prospectus. In addition, risks associated with any investment in our securities may be described in the applicable prospectus supplement and our other filings with the Securities and Exchange Commission, as described in the “Risk Factors” section on page 1 of this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is November 25, 2024.

Table of Contents

i

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we have filed with the U.S. Securities and Exchange Commission (the “SEC”) using a “shelf” registration process. Under this shelf registration process, we may offer for sale the senior debt securities this prospectus describes in one or more offerings. In this prospectus, we sometimes refer to such senior debt securities as the “senior debt securities,” the “debt securities” or the “securities.” This prospectus provides you with a general description of the securities we may offer. Each time we use this prospectus to offer securities, we will provide a prospectus supplement and, if applicable, a pricing supplement that will describe the specific terms of the offering. The prospectus supplement and any pricing supplement may also add to, update or change the information contained in this prospectus. Please carefully read this prospectus, the prospectus supplement and any pricing supplement, in addition to the information contained in the documents we refer to under the heading “Where You Can Find More Information.”

THE COMPANY

Oceaneering International, Inc. is a global technology company delivering engineered services and products and robotic solutions to the offshore energy, defense, aerospace, manufacturing and entertainment industries. Oceaneering was organized as a Delaware corporation in 1969 out of the combination of three diving service companies founded in the early 1960s. Since our establishment, we have concentrated on the development and marketing of underwater services and products to meet customer needs requiring the use of advanced technology. The continued evolution of applying our advanced technologies has expanded our presence into numerous adjacent markets focused on autonomous robotics. We believe we are one of the world’s largest underwater services contractors. The services and products we provide to the energy industry include remotely operated vehicles, survey and positioning services, specialty subsea hardware, engineering and project management, subsea intervention services, including manned diving and asset integrity and non-destructive testing services. We operate in numerous countries throughout the world but currently focus most of our operations on markets in the United States, Africa, Asia, Australia, United Kingdom, Brazil, and Norway.

In this prospectus, we refer to Oceaneering International, Inc. and its consolidated subsidiaries as “we,” “us” or “Oceaneering,” unless we specifically state otherwise or the context indicates otherwise. Our principal executive offices are located at 5875 North Sam Houston Parkway West, Suite 400 Houston, Texas 77086, and our telephone number at that location is (713) 329-4500.

RISK FACTORS

Investing in our securities involves risks. You should carefully consider the specific risks set forth under the caption “Risk Factors” in the applicable prospectus supplement, and under the caption “Risk Factors” in any of our filings with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), incorporated by reference in this prospectus, before making an investment decision. For more information, see “Where You Can Find More Information.”

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. The SEC maintains a website that contains information we have filed electronically with the SEC, which you can access at www.sec.gov. You can also obtain information about us at the offices of the New York Stock Exchange, 11 Wall Street, New York, New York 10005.

1

Our website is located at www.oceaneering.com. Our filings with the SEC are available, free of charge, through our website, as soon as reasonably practicable after those reports or filings are electronically filed with or furnished to the SEC. Information contained on or accessible from our website or any other website is not incorporated into this prospectus and does not constitute a part of this prospectus.

This prospectus is part of a registration statement we have filed with the SEC relating to the securities we may offer. As permitted by SEC rules, this prospectus does not contain all the information we have included in the registration statement and the accompanying exhibits we have filed with the SEC. You may refer to the registration statement and exhibits for more information about us and the securities. The registration statement and exhibits are available at the SEC’s public reference room or through its website.

The SEC allows us to “incorporate by reference” the information we have filed with it, which means that we can disclose important information to you by referring you to those documents. The information we incorporate by reference is an important part of this prospectus, and later information that we file with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (other than information “furnished” and not “filed” with the SEC, unless we specifically provide that such “furnished” information is to be incorporated by reference) after the date of this prospectus and until the termination of this offering. The documents we incorporate by reference are:

You may request a copy of these filings, other than an exhibit to these filings unless we have specifically incorporated that exhibit by reference into the filing, at no cost, by writing to or telephoning us at:

Oceaneering International, Inc.

5875 North Sam Houston Parkway West, Suite 400

Houston, Texas 77086

Attention: Corporate Secretary

Telephone: (713) 329-4500

We have not authorized anyone to provide any information or to make any representations other than those contained or incorporated by reference in this prospectus, the prospectus supplement or any free writing prospectus prepared by or on behalf of us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. We are not making an offer of the securities in any jurisdiction where the offer is not permitted. You should assume that the information in this prospectus, the prospectus supplement and any free writing prospectus is accurate only as of their respective dates and that any information we have incorporated by reference is accurate only as of the date of the document incorporated by reference.

2

FORWARD-LOOKING STATEMENTS

This prospectus, including the documents incorporated by reference in this prospectus, contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. These statements may include projections and estimates concerning the timing and success of specific projects and our future orders, revenue, income and capital spending. Forward-looking statements are generally accompanied by words such as “estimate,” “plan,” “project,” “predict,” “believe,” “expect,” “anticipate,” “plan,” “forecast,” “budget,” “goal,” “may,” “should,” or other words that convey the uncertainty of future events or outcomes. In particular, these forward-looking statements include, but are not limited to, statements that relate to, or statements that are subject to risks, contingencies or uncertainties that relate to:

These forward-looking statements speak only as of the date of this prospectus; we disclaim any obligation to update these statements unless required by securities law, and we caution you not to rely on them unduly. We have based these forward-looking statements on our current expectations and assumptions about future events. While our management considers these expectations and assumptions to be reasonable, they are inherently

3

subject to significant business, economic, competitive, regulatory and other risks, contingencies and uncertainties, most of which are difficult to predict and many of which are beyond our control. These risks, contingencies and uncertainties relate to, among other matters, the following:

4

We believe the items we have outlined above are important factors that could cause estimates in our financial statements to differ materially from actual results and those expressed in a forward-looking statement made in this prospectus, any prospectus supplement, the documents incorporated herein by reference or elsewhere by us or on our behalf. We have discussed many of these factors in more detail elsewhere in the documents we have incorporated by reference and may discuss these factors in more detail in any prospectus supplement. These factors are not necessarily all the factors that could affect us. Unpredictable or unanticipated factors we have not discussed in this prospectus could also have material adverse effects on actual results of matters that are the subject of our forward-looking statements. We do not intend to update our description of important factors each time a potential important factor arises, except as required by applicable securities laws and regulations. We advise investors that they should (1) be aware that factors not referred to above could affect the accuracy of our forward-looking statements and (2) use caution and common sense when considering our forward-looking statements.

5

USE OF PROCEEDS

Unless we inform you otherwise in a prospectus supplement, we expect to use the net proceeds from the sale of the securities under this prospectus for general corporate purposes. These purposes may include the repayment or refinancing of indebtedness and funding for acquisitions, working capital requirements, capital expenditures and repurchases and redemptions of securities. Pending any specific application, we may initially invest funds in short-term marketable securities or apply them to the reduction of short-term indebtedness.

DESCRIPTION OF DEBT SECURITIES

This prospectus describes certain general terms and provisions of our senior debt securities. The debt securities will be our general unsecured obligations. We will issue the debt securities under a senior indenture between us and Computershare Trust Company, N.A. (as successor to Wells Fargo Bank, National Association) as trustee, dated November 21, 2014. The indenture has been qualified under the Trust Indenture Act of 1939. In this description, we sometimes refer to the senior indenture as the “indenture.”

We have summarized certain provisions of the indenture below. You should read the indenture for more details regarding the provisions described below and for other provisions that may be important to you. We have filed the indenture with the SEC as an exhibit to the registration statement, and we will include any other instrument establishing the terms of any debt securities we offer as an exhibit to a filing we will make with the SEC in connection with that offering. This section does not describe every aspect of the indenture or the debt securities. The specific terms of any debt securities will be described in the applicable prospectus supplement relating to the debt securities being offered. See “Where You Can Find More Information.”

In this summary description of the debt securities, all references to “Oceaneering,” “we” or “us” mean Oceaneering International, Inc. only, unless we state otherwise or the context clearly indicates otherwise.

General

The debt securities will constitute our senior debt and will rank equally with all of our unsecured and unsubordinated debt. The amount of debt that may be issued under the indenture is unlimited, and, unless we inform you otherwise in the prospectus supplement, the indenture does not limit the amount of other unsecured debt or securities we may incur or issue. We may issue debt securities under the indenture from time to time in one or more series, each in an amount we authorize prior to issuance.

We conduct a substantial part of our operations through our subsidiaries, and our subsidiaries generate a significant part of our operating income and cash flow. As a result, distributions or advances from our subsidiaries are important sources of funds to meet our debt service obligations. Contractual provisions or laws, as well as our subsidiaries’ financial condition and operating requirements, may limit our ability to obtain from our subsidiaries cash that we need to pay our debt service obligations, including payments on the debt securities. In addition, holders of the debt securities will have a junior position to the claims of creditors of our subsidiaries on their assets and earnings.

Our right to receive any assets of any subsidiary, and therefore the right of the holders of our debt securities to participate in those assets, will be effectively subordinated to the claims of that subsidiary’s creditors, including trade creditors. In addition, even if we are a creditor of any subsidiary, our rights as a creditor would be subordinate to any security interest in the assets of that subsidiary and any indebtedness of that subsidiary senior to that held by us.

We may issue the debt securities of any series in definitive form or as a book-entry security in the form of a global security registered in the name of a depositary we designate.

6

We may issue the debt securities in one or more series with various maturities, and we may sell those debt securities at par, at a premium or with an original issue discount.

Terms

A prospectus supplement relating to any series of debt securities being offered will include specific terms relating to the offering. These terms will include some or all of the following:

If we sell any of the debt securities for any foreign currency or currency unit or if payments on the debt securities are payable in any foreign currency or currency unit, we will describe in the prospectus supplement the restrictions, elections, tax consequences, specific terms and other information relating to those debt securities and the foreign currency or currency unit.

Consolidation, Merger and Sale of Assets

The indenture generally permits a consolidation, amalgamation or merger between us and another entity. It also permits the sale by us of our assets substantially as an entirety. The indenture provides, however, that we

7

may consolidate or amalgamate with another entity to form a new entity or merge into any other entity or transfer or dispose of our assets substantially as an entirety to any other entity only if:

On the assumption by the successor of the obligations under the indenture, the successor will be substituted for us, and we will be relieved of any further obligation under the indenture and the debt securities.

Events of Default

Unless we inform you otherwise in the prospectus supplement, the following will be events of default with respect to a series of debt securities:

A default under one series of debt securities will not necessarily be a default under another series. The trustee may withhold notice to the holders of the debt securities of any default or event of default, except in any payment on the debt securities, if the trustee in good faith determines that withholding notice is in the interest of the holders of the debt securities.

If an event of default for any series of debt securities occurs and is continuing, the trustee or the holders of at least 25% in principal amount of the outstanding debt securities of the series affected by the default, or, in some cases, 25% in principal amount of all debt securities affected, voting as one class, may declare the principal of and all accrued and all unpaid interest on those debt securities to be immediately due and payable. If an event of default relating to events of bankruptcy, insolvency or reorganization occurs, the principal of and all accrued and unpaid interest on all the debt securities will become immediately due and payable without any action on the part of the trustee or any holder. The holders of a majority in principal amount of the outstanding debt securities of the series affected by the default, or of all debt securities affected, voting as one class, may in some cases rescind this accelerated payment requirement. Depending on the terms of our other indebtedness, an event of default under the indenture may give rise to cross defaults on our other indebtedness.

A holder of a debt security of any series will be able to pursue any remedy under the indenture only if:

8

This provision will not, however, affect the right of a holder of a debt security to sue for enforcement of any overdue payment.

In most cases, holders of a majority in principal amount of the outstanding debt securities of a series, or of all debt securities affected, voting as one class, will be able to direct the time, method and place of:

The indenture requires us to file with the trustee each year a written statement as to our compliance with the covenants contained in the indenture.

Modification and Waiver

We may amend or supplement the indenture if the holders of a majority in principal amount of the outstanding debt securities of all series issued under the indenture and affected by the amendment or supplement, acting as one class, consent to it. Without the consent of the holder of each debt security affected, however, no amendment or supplement may:

We and the trustee may agree to amend or supplement the indenture or waive any provision of the indenture without the consent of any holders of debt securities in some circumstances, including:

9

The holders of a majority in principal amount of the outstanding debt securities of any series, or of all debt securities affected, voting as one class, may waive any existing or past default or event of default with respect to those debt securities. Those holders may not, however, waive any default or event of default in any payment on any debt security or compliance with a provision that cannot be amended or supplemented without the consent of each holder affected.

Discharge and Defeasance

We will be discharged from all obligations under the indenture with respect to any series of debt securities, except for surviving obligations relating to any conversion rights and to register the transfer or exchange of the debt securities, if:

To exercise our right to be discharged, we must deliver to the trustee an opinion of counsel and an officers’ certificate stating that all conditions precedent to the satisfaction and discharge of the indenture have been complied with.

In addition to our right of discharge described above, if we deposit with the trustee funds or government securities sufficient to make payments on the debt securities of a series on the dates those payments are due and payable, then, at our option, either of the following will occur:

10

If we defease a series of debt securities, the holders of the debt securities of the series affected will not be entitled to the benefits of the indenture, except for our obligations to:

Unless we inform you otherwise in the prospectus supplement, we will be required to deliver to the trustee an opinion of counsel that the deposit and related defeasance would not cause the holders of the debt securities to recognize income, gain or loss for United States federal income tax purposes. If we elect legal defeasance, that opinion of counsel must be based on a ruling from the United States Internal Revenue Service or a change in law to that effect.

Governing Law

New York law will govern the indenture and the debt securities, except to the extent that the Trust Indenture Act of 1939 is applicable.

Trustee

Computershare Trust Company, N.A. (as successor to Wells Fargo Bank, National Association) is the trustee under the indenture.

If an event of default occurs and is continuing, the trustee must use the degree of care and skill of a prudent person in the conduct of such person’s own affairs. The trustee will become obligated to exercise any of its powers under the indenture at the request of any of the holders of any debt securities only after those holders have offered the trustee indemnity satisfactory to the trustee.

The indenture limits the right of the trustee, if it becomes one of our creditors, to obtain payment of claims or to realize on certain property received for any such claim, as security or otherwise. The trustee may engage in other transactions with us. If it acquires any conflicting interest, however, it must eliminate that conflict or resign.

Form, Exchange, Registration and Transfer

We will issue the debt securities in registered form, without interest coupons. We will not charge a service charge for any registration of transfer or exchange of the debt securities. We may, however, require the payment of any tax or other governmental charge payable for that registration.

Debt securities of any series will be exchangeable for other debt securities of the same series with the same total principal amount and the same terms but in different authorized denominations in accordance with the indenture. Holders may present debt securities for registration of transfer at the office of the security registrar or any transfer agent we designate. The security registrar or transfer agent will effect the transfer or exchange when it is satisfied with the documents of title and identity of the person making the request.

Unless we inform you otherwise in the prospectus supplement, we will appoint the trustee under the indenture as security registrar for the debt securities we issue under the indenture. If the prospectus supplement refers to any transfer agent initially designated by us, we may at any time rescind that designation or approve a change in the location through which any transfer agent acts. We will be required to maintain an office or agency for transfers and exchanges in each place of payment. We may at any time designate additional transfer agents for any series of debt securities or rescind the designation of any transfer agent.

11

In the case of any redemption, neither the security registrar nor the transfer agent will be required to register the transfer or exchange of any debt security:

Payment and Paying Agent

Unless we inform you otherwise in the prospectus supplement, we will make payments on the debt securities in U.S. dollars at the office of the trustee or any paying agent we designate. At our option, we may make payments by check mailed to the holder’s registered address or, with respect to global debt securities, by wire transfer. Unless we inform you otherwise in the prospectus supplement, we will make interest payments to the person in whose name the debt security is registered at the close of business on the record date for the interest payment.

Unless we inform you otherwise in the prospectus supplement, we will designate the trustee under the indenture as our paying agent for payments on debt securities we issue under the indenture. We may at any time designate additional paying agents or rescind the designation of any paying agent or approve a change in the office through which any paying agent acts.

Subject to the requirements of any applicable abandoned property laws, the trustee and paying agent will repay to us upon written request any funds held by them for payments on the debt securities that remain unclaimed for two years after the date upon which that payment has become due. After repayment to us, holders entitled to those funds must look only to us for payment.

Book-Entry Debt Securities

We may issue the debt securities of a series in the form of one or more global debt securities that would be deposited with a depositary or its nominee identified in the prospectus supplement. We may issue global debt securities in either temporary or permanent form. We will describe in the prospectus supplement the terms of any depositary arrangement and the rights and limitations of owners of beneficial interests in any global debt security.

12

PLAN OF DISTRIBUTION

We may sell the securities being offered under this prospectus in and outside the United States through underwriters or dealers, directly to purchasers or through agents.

Sale Through Underwriters or Dealers

If we use underwriters in the sale of the securities, the underwriters will acquire the securities for their own account. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless we inform you otherwise in the prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to several conditions, and the underwriters will be obligated to purchase all the securities being offered if they purchase any of them. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers.

During and after an offering through underwriters, the underwriters may purchase and sell the securities in the open market. These transactions may include overallotment and stabilizing transactions and purchases to cover syndicate short positions created in connection with the offering. The underwriters may also impose a penalty bid, whereby selling concessions allowed to syndicate members or other broker-dealers for the offered securities sold for their account may be reclaimed by the syndicate if such offered securities are repurchased by the syndicate in stabilizing or covering transactions. These activities may stabilize, maintain or otherwise affect the market price of the offered securities, which may be higher than the price that might otherwise prevail in the open market. If commenced, these activities may be discontinued at any time.

If we use dealers in the sale of securities, we will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. The dealers participating in any sale of the securities may be deemed to be underwriters within the meaning of the Securities Act of 1933, as amended (the “Securities Act”), with respect to any sale of those securities. We will include in the prospectus supplement the names of the dealers and the terms of the transaction.

Direct Sales and Sales Through Agents

We may sell the securities directly. In that event, no underwriters or agents would be involved. We may also sell the securities through agents we designate from time to time. In the prospectus supplement, we will name any agent involved in the offer or sale of the securities being offered, and we will describe any commissions payable by us to the agent. Unless we inform you otherwise in the prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. We will describe the terms of any such sales in the prospectus supplement.

Delayed Delivery Contracts

If we so indicate in the prospectus supplement, we may authorize agents, underwriters or dealers to solicit offers from various types of institutions to purchase securities from us at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions the prospectus supplement describes. The prospectus supplement will describe the commission payable for solicitation of those contracts.

13

General Information

We may have agreements with the agents, dealers and underwriters to indemnify them against civil liabilities, including liabilities under the Securities Act, or to contribute with respect to payments that the agents, dealers or underwriters may be required to make. Agents, dealers and underwriters may be customers of, engage in transactions with or perform services for us in the ordinary course of their businesses.

14

LEGAL MATTERS

Baker Botts L.L.P., Houston, Texas, our outside counsel, will issue an opinion about the legality of any securities we offer through this prospectus. Any underwriters will be advised about issues relating to any offering by their own legal counsel.

EXPERTS

The consolidated financial statements of Oceaneering International, Inc. and subsidiaries appearing in Oceaneering International, Inc.’s Annual Report (Form 10-K) for the year ended December 31, 2023, and the effectiveness of Oceaneering International, Inc.’s and subsidiaries’ internal control over financial reporting as of December 31, 2023 have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated herein by reference. Such consolidated financial statements and management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2023 are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

15

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution.

The following table sets forth expenses payable by Oceaneering in connection with the issuance and distribution of the debt securities being registered.

Item 15. Indemnification of Directors and Officers.

Section 145(a) of the Delaware General Corporation Law (“DGCL”) provides, in general, that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation), because he or she is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust, or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by the person in connection with such action, suit or proceeding, if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation and, with respect to any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful.

Section 145(b) of the DGCL provides, in general, that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action or suit by or in the right of the corporation to procure a judgment in its favor because the person is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees) actually and reasonably incurred by the person in connection with the defense or settlement of such action or suit if he or she acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation, except that no indemnification shall be made with respect to any claim, issue or matter as to which he or she shall have been adjudged to be liable to the corporation unless and only to the extent that the Court of Chancery or other adjudicating court determines that, despite the adjudication of liability but in view of all of the circumstances of the case, he or she is fairly and reasonably entitled to indemnity for such expenses which the Court of Chancery or other adjudicating court shall deem proper.

II-1

Section 145(e) of the DGCL provides that expenses (including attorneys’ fees) incurred by an officer or director in defending any civil, criminal, administrative or investigative action, suit or proceeding may be paid by the corporation in advance of the final disposition of such action, suit or proceeding upon receipt of an undertaking by or on behalf of such director or officer to repay such amount if it shall ultimately be determined that such person is not entitled to be indemnified by the corporation as authorized by Section 145 of the DGCL. Section 145(e) of the DGCL further provides that such expenses (including attorneys’ fees) incurred by former directors and officers or other employees or agents of the corporation may be so paid upon such terms and conditions as the corporation deems appropriate.

Section 145(g) of the DGCL provides, in general, that a corporation may purchase and maintain insurance on behalf of any person who is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise against any liability asserted against such person and incurred by such person in any such capacity, or arising out of his or her status as such, whether or not the corporation would have the power to indemnify the person against such liability under Section 145 of the DGCL.

Article VI of Oceaneering’s amended and restated bylaws provides that Oceaneering will indemnify and hold harmless each of its directors and officers, to the fullest extent applicable law permits, from and against any and all judgments, penalties, fines (including excise taxes), amounts paid in settlement and, subject to certain limitations, expenses arising out of any claim, other than a claim brought by or on behalf of Oceaneering or a related enterprise, by reason of the fact that: (1) such person is or was a director or an officer of Oceaneering; or (2) while a director or an officer, such person served, at the request of Oceaneering, as a director, officer, manager, administrator, employee, agent or representative of a related enterprise (any person described in item 1 or 2, is referred to as an “Eligible Indemnitee”). For claims brought by or on behalf of Oceaneering or a related enterprise, Oceaneering will indemnify an Eligible Indemnitee for all expenses reasonably incurred as a result of such claim if the Eligible Indemnitee is not adjudged liable under such claim or if the court making the adjudication of liability against the Eligible Indemnitee determines that despite such an adjudication, the circumstances in the case warrant that the Eligible Indemnitee be indemnified for expenses reasonably incurred. Article VI of Oceaneering’s amended and restated bylaws also provides that Oceaneering may advance funds to an Eligible Indemnitee to cover expenses he or she incurs in defending against any action, suit or proceeding that may give rise to a right to indemnification upon receipt of an undertaking by or on behalf of such person to repay such amount if it is ultimately determined that such person is not entitled to be indemnified by Oceaneering. Oceaneering may, to the extent and in the manner applicable law permits, indemnify and advance expenses to persons other than present or former directors or officers of Oceaneering, when authorized by the Board of Directors of Oceaneering or other appropriate corporate action.

Oceaneering has also entered into indemnification agreements with each of its directors and executive officers. These indemnification agreements generally provide Oceaneering’s directors and executive officers with a contractual right of indemnification to the same extent provided by Section 145 of the DGCL and a contractual right to advancement of expenses consistent with the provisions of Article VI of Oceaneering’s amended and restated bylaws.

Additionally, Oceaneering’s restated certificate of incorporation, as amended, contains a provision that eliminates the personal liability of directors to Oceaneering or its stockholders for monetary damages for breach of the director’s fiduciary duty of care as a director. As a result, stockholders may be unable to recover monetary damages against directors for negligent or grossly negligent acts or omissions in violation of their duty of care. The provision does not change the liability of a director for breach of such director’s of loyalty to Oceaneering or to stockholders, for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law, for the declaration or payment of dividends in violation of Delaware law or in respect of any transaction from which that director receives an improper personal benefit.

II-2

Oceaneering also maintains directors’ and officers’ liability insurance for its directors and officers that protects them from certain losses arising from claims or charges made against them in their capacities as directors or officers of Oceaneering.

Agreements Oceaneering may enter into with underwriters, dealers and agents who participate in the distribution of Oceaneering’s securities may contain provisions relating to the indemnification of Oceaneering’s officers and directors.

Item 16. Exhibits.*

Index to Exhibits

Item 17. Undertakings

II-3

provided, however, that paragraphs (1)(i), (1)(ii) and (1)(iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

The undersigned Registrant undertakes that in a primary offering of securities of the undersigned Registrant pursuant to the registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned Registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

II-4

II-5

SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, Oceaneering International, Inc. certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Houston, the State of Texas, on November 25, 2024.

POWER OF ATTORNEY

Each person whose signature appears below appoints Roderick A. Larson, Alan R. Curtis and Jennifer F. Simons, and each of them, severally, as his or her true and lawful attorney or attorneys-in-fact and agent or agents, each of whom shall be authorized to act with or without the other, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead in his or her capacity as a director or officer or both, as the case may be, of Oceaneering International, Inc., to sign any and all amendments (including post-effective amendments) to this Registration Statement, and all documents or instruments necessary or appropriate to enable Oceaneering International, Inc. to comply with the Securities Act of 1933, as amended, and to file the same with the Securities and Exchange Commission, with full power and authority to each of said attorneys-in-fact and agents to do and perform in the name and on behalf of each such director or officer, or both, as the case may be, each and every act whatsoever that is necessary, appropriate or advisable in connection with any or all of the above-described matters and to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or any of them or their substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities indicated on November 25, 2024.

Exhibit 5.1

November 25, 2024

Oceaneering International, Inc.

5875 North Sam Houston Parkway West, Suite 400

Houston, Texas 77086

Ladies and Gentlemen:

As set forth in the Registration Statement on Form S-3 (the “Registration Statement”) to be filed on the date hereof by Oceaneering International, Inc., a Delaware corporation (“Oceaneering”), with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Act”), relating to the offering of unsecured senior debt securities (the “Debt Securities”) that may be issued and sold by Oceaneering from time to time pursuant to Rule 415 under the Act, certain legal matters in connection with such securities are being passed upon for you by us. At your request, this letter is being furnished to you for filing as Exhibit 5.1 to the Registration Statement.

Each series of Debt Securities will be issued pursuant to the Senior Indenture between Oceaneering and Computershare Trust Company, N.A. (as successor to Wells Fargo Bank, National Association) as trustee, dated November 21, 2014 (the “Indenture”), as such Indenture will be supplemented, in connection with the issuance of each such series, by a supplemental indenture, officers’ certificate or other writing thereunder establishing the form and terms of such series of Debt Securities.

In our capacity as your counsel in the connection referred to above, we have examined originals, or copies certified or otherwise identified, of Oceaneering’s Restated Certificate of Incorporation and Amended and Restated Bylaws, each as amended to date (the “Charter Documents”), the form of the Registration Statement (including the base prospectus which forms a part of the Registration Statement), the Indenture and corporate records of Oceaneering, including minute books as furnished to us by you, certificates of public officials and of representatives of Oceaneering, statutes and other instruments and documents as a basis for the opinions hereinafter expressed. In giving the opinions set forth herein, we have relied, to the extent we deemed appropriate, with respect to factual matters, upon certificates, statements or other representations of officers or other representatives of Oceaneering and of public officials, and we have assumed, without independent investigation, that all signatures on documents we have examined are genuine, all documents submitted to us as originals are authentic and complete, all documents submitted to us as copies conform to the original copies of those documents and those original copies are authentic and complete. In connection with the opinions set forth herein, we have assumed that:

(a) the Registration Statement and any amendments thereto (including post-effective amendments) will have become effective under the Act;

Oceaneering International, Inc.		November 25, 2024

(b) Oceaneering will have prepared and filed with the Commission under the Act a prospectus supplement describing the Debt Securities offered thereby;

(c) Oceaneering will have offered, issued and sold the Debt Securities in compliance with applicable federal and state securities laws and in the manner stated in the Registration Statement and the appropriate prospectus supplement;

(d) the Board of Directors of Oceaneering or, to the extent permitted by the General Corporation Law of the State of Delaware and the Charter Documents of Oceaneering, a duly constituted and acting committee thereof (such Board of Directors of Oceaneering or committee thereof being hereinafter referred to as the “Board”) will have taken all necessary corporate action to authorize the issuance of the Debt Securities and approve the terms of the offering and sale of such Debt Securities and related matters;

(e) a definitive purchase, underwriting or similar agreement with respect to any Debt Securities offered by Oceaneering will have been duly authorized and validly executed and delivered by Oceaneering and the other parties thereto (a “Purchase Agreement”);

(f) all Debt Securities, and any certificates in respect thereof, will be delivered in accordance the provisions of the applicable Purchase Agreement approved by the Board upon payment of the consideration therefor provided for therein; and

(g) with respect to each series of Debt Securities issued under the Indenture:

On the basis of and subject to the assumptions, limitations and qualifications set forth herein, we are of the opinion that the Debt Securities will, when issued, constitute legal, valid and binding obligations of Oceaneering, enforceable against Oceaneering in accordance with their respective terms, except as that enforcement is subject to (a) any applicable bankruptcy, insolvency, reorganization, moratorium, fraudulent conveyance or transfer or other laws relating to or affecting creditors’ rights generally, (b) general principles of equity (regardless of whether such enforceability is considered in a proceeding in equity or at law) and (c) any implied covenants of good faith and fair dealing.

We limit the opinions we express above in all respects to matters of the contract law of the State of New York, as in effect on the date hereof.

- 2 -

Oceaneering International, Inc.		November 25, 2024

We hereby consent to the filing of this opinion of counsel as Exhibit 5.1 to the Registration Statement. We also consent to the reference to our Firm under the heading “Legal Matters” in the prospectus forming a part of the Registration Statement. In giving this consent, we do not hereby admit that we are in the category of persons whose written consent Section 7 of the Act requires to be filed.

- 3 -

Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the reference to our firm under the caption “Experts” in this Registration Statement (Form S-3) and related Prospectus of Oceaneering International, Inc. for the registration of debt securities and to the incorporation by reference therein of our reports dated February 23, 2024, with respect to the consolidated financial statements of Oceaneering International, Inc. and subsidiaries, and the effectiveness of internal control over financial reporting of Oceaneering International, Inc. and subsidiaries, included in its Annual Report (Form 10-K) for the year ended December 31, 2023, filed with the Securities and Exchange Commission.

/s/ ERNST & YOUNG LLP

Houston, Texas

November 25, 2024

Exhibit 25.1

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM T-1

STATEMENT OF ELIGIBILITY

UNDER THE TRUST INDENTURE ACT OF 1939

OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE

COMPUTERSHARE TRUST COMPANY, NATIONAL ASSOCIATION

(Exact name of trustee as specified in its charter)

Law Department

Computershare Trust Company, National Association

150 Royall Street, Canton, MA

02021

(781) 575-2000

(Name, address and telephone number of agent for service)

Oceaneering International, Inc.

(Exact name of obligor as specified in its charter)

Senior Debt Securities

(Title of the indenture securities)

SIGNATURE

Pursuant to the requirements of the Trust Indenture Act of 1939, the trustee, Computershare Trust Company, National Association, a national banking association, organized and existing under the laws of the United States, has duly caused this statement of eligibility to be signed on its behalf by the undersigned, thereunto duly authorized, all in the City of St. Paul, and State of Minnesota, on the 20^th day of November, 2024.

EXHIBIT 2

A copy of the Comptroller of the Currency Certificate of Corporate Existence for Computershare Trust Company, National Association, dated May 7, 2024.

EXHIBIT 3

A copy of the Comptroller of the Currency Certification of Fiduciary Powers for Computershare Trust Company, National Association, dated May 7, 2024.

EXHIBIT 6

CONSENT OF THE TRUSTEE

Pursuant to the requirements of Section 321 (b) of the Trust Indenture Act of 1939, and in connection with the proposed issue of debt securities, Computershare Trust Company, National Association hereby consents that reports of examinations by Federal, State, Territorial or District authorities may be furnished by such authorities to the Securities and Exchange Commission upon request therefore.

November 20, 2024

EXHIBIT 7

Consolidated Report of Condition of

COMPUTERSHARE TRUST COMPANY, NATIONAL ASSOCIATION

150 Royall Street, Canton, MA 02021

at the close of business June 30, 2024.

2

I, Greg Brandt, Assistant Controller of the above named bank do hereby declare that this Report of Condition is true and correct to the best of my knowledge and belief.

3