Exhibit 4.1

EXECUTION VERSION

This THIRD SUPPLEMENTAL INDENTURE (this “ Third Supplemental Indenture ”), dated as of February 22, 2018, among SEASPAN CORPORATION, a corporation duly organized and existing under the laws of the Republic of The Marshall Islands (the “ Company ”), the Guarantors (as defined herein) and THE BANK OF NEW YORK MELLON, as trustee (the “ Trustee ”).

RECITALS

WHEREAS, the Company and the Trustee have heretofore executed and delivered an indenture, dated as of October 10, 2017 (the “ Base Indenture ”), between the Company and the Trustee, as amended and supplemented by a second supplemental indenture, dated as of February 14, 2018 (the “ Second Supplemental Indenture ”), among the Company, the Guarantors and the Trustee, providing for the issuance of 5.50% Senior Notes due 2025 (the “ Notes ”);

WHEREAS, Section 7.01 of the Second Supplemental Indenture provides, among other things, that the Company and the Trustee may, without the consent of Holders, enter into indentures supplemental to the Base Indenture to secure the Notes;

WHEREAS, pursuant to Section 7.01(7) of the Second Supplemental Indenture, the Trustee and the Company are authorized to execute and deliver this Third Supplemental Indenture to amend or supplement the Indenture, without the consent of any Holder of Securities; and

WHEREAS, all actions required to be taken by the Company and each of the Guarantors under the Indenture to make this Third Supplemental Indenture a valid, binding and legal agreement of the Company and each of the Guarantors, have been done.

NOW, THEREFORE, in consideration of the premises and for other good and valuable consideration, the sufficiency and adequacy of which are hereby acknowledged, the parties hereto hereby agree as follows:

ARTICLE I

DEFINITIONS AND INCORPORATION BY REFERENCE

Section 1.01. Definitions .

(a)    The Base Indenture collectively with the Second Supplemental Indenture and this Third Supplemental Indenture is hereinafter sometimes collectively referred to as the “ Indenture .”

(b)    All capitalized terms used herein and not otherwise defined below shall have the meanings ascribed thereto in the Base Indenture as amended and supplemented by the Second Supplemental Indenture.

“ Collateral ” means 100 shares of the capital stock, par value $0.01 per share, of Seaspan Investment I Ltd. owned by the Company and evidenced by certificate number 001 and all proceeds and products of the foregoing, all books and records at any time evidencing or relating to the foregoing, all supporting obligations related thereto, and all accessions to, substitutions and replacements for, and profits and products of, the foregoing, and any and all proceeds of any indemnity, warranty or guaranty payable to the Company from time to time with respect to the foregoing.

“ Pledge Agreement ” means the Pledge Agreement, dated as of February 22, 2018, between the Company and the Trustee, as the same may from time to time be amended.

“ Seaspan Investment ” means Seaspan Investment I Ltd, a corporation duly organized and existing under the laws of the Republic of The Marshall Islands.

ARTICLE II

APPLICATION OF SUPPLEMENTAL INDENTURE

Section 2.01. Application of this Third Supplemental Indenture . Notwithstanding any other provision of this Third Supplemental Indenture, the provisions of this Third Supplemental Indenture are expressly and solely for the benefit of the Trustee and the Holders of the Notes and any such provisions shall not be deemed to apply to any other Securities issued under the Indenture and shall not be deemed to amend, modify or supplement the Base Indenture for any purpose other than with respect to the Notes.

ARTICLE III

COLLATERAL

Section 3.01. Collateral . The Company hereby represents and warrants that as of the date of this Third Supplemental Indenture, (a) the only outstanding shares of capital stock of Seaspan Investment are the 100 shares of capital stock, par value $0.01 per share, owned by the Company and evidenced by certificate number 001 and (b) Seaspan Investment has no liabilities and its only assets are Seaspan Investment’s investment in Greater China Industrial Investments LLC, a limited liability company duly organized and existing under the laws of the Republic of The Marshall Islands. The Company shall not permit Seaspan Investment to issue any additional shares of capital stock unless such additional shares are issued to the Company or any Subsidiary of the Company and a lien on and security interest in all of the right, title and interest of the Company or such Subsidiary of the Company in, to and under such additional shares of capital stock is pledged, assigned and granted for the ratable benefit of the Trustee and the Holders.

ARTICLE IV

EVENTS OF DEFAULT

Section 4.01. Additional Events of Default . In addition to the Events of Default in Article 5 of the Base Indenture, as amended and supplemented by Article VI of the Second Supplemental Indenture, solely for the purposes of the Notes (and not in relation to any other series of Securities), the following shall be an Event of Default with respect to the Notes:

(a)    the Pledge Agreement or any security interest or lien purported to be created by the Pledge Agreement ceases for any reason to be enforceable or the Company, or any Person acting on behalf of the Company, denies or disaffirms, in writing, any obligation of the Company set forth in or arising under the Pledge Agreement.

ARTICLE V

AMENDMENTS TO THE PLEDGE AGREEMENT

Section 5.01. Amendments, Supplements and Waivers to the Pledge Agreement . With the consent of the Holders of each Outstanding Note, including consents obtained in connection with a tender offer or exchange offer, by Act of said Holders delivered to the Company and the Trustee, the Company (when authorized by or pursuant to a Company’s Board Resolution) and the Trustee (upon Company Order) may enter into an amendment, supplement or waiver to the Pledge Agreement or the provisions in the Indenture dealing with the Collateral or the Pledge Agreement.

2

Section 5.02. E xecution of Amendments, Supplements and Waivers . As a condition to executing any supplement, amendment or waiver permitted by this Article V, the Trustee shall be entitled to receive, and shall be fully protected in relying upon, an Opinion of Counsel and an Officer’s Certificate each stating that the execution of such supplemental indenture, amendment or waiver is authorized or permitted by the Indenture and that all conditions precedent to the execution of such supplement, amendment or waiver have been fulfilled. The Trustee may, but shall not be obligated to, enter into any such supplement, amendment or waiver which affects the Trustee’s own rights, duties or immunities under the Indenture, the Pledge Agreement or otherwise.

ARTICLE VI

PLEDGE AGREEMENT AND COLLATERAL

Section 6.01. P ledge Agreement Authorization . The Holders hereby authorize and direct the Trustee to execute and deliver the Pledge Agreement and to take such actions on its behalf under the provisions of the Pledge Agreement and to exercise such powers and perform such duties as are delegated to the Trustee by the terms of the Pledge Agreement, together with such actions and powers as are reasonably incidental thereto.

Section 6.02. E xtension of Rights and Protections . All rights and protections of the Trustee set forth in the Indenture, including without limitation its right to indemnification and reimbursement, shall extend to the Trustee in connection with its actions or omissions under the Pledge Agreement.

Section 6.03. A dditional Rights of the Trustee . In addition to the rights and protections of the Trustee under the Indenture, the Trustee shall have the following additional rights and protections under this Third Supplemental Indenture and the Pledge Agreement:

(a)    the Trustee shall not be responsible for, nor incur any liability with respect to, (i) the existence, genuineness or value of any of the Collateral or for the validity, perfection, priority or enforceability of the security interest in any of the Collateral, whether impaired by operation of law or by reason of any action or omission to act on its part under this Third Supplemental Indenture or the Pledge Agreement, or for the filing, form, content or renewal of any UCC financing statements, fixture filings, mortgages, deeds of trust or such other documents or instruments related to the Collateral, (ii) the validity, sufficiency or condition of the Collateral or any agreement or assignment related thereto, (iii) the validity of the title of the Company to the Collateral, (iv) insuring the Collateral or (v) the payment of taxes, charges or assessments upon the Collateral;

(b)    the Trustee shall have no duty to the Holders as to any Collateral in its possession or in the possession of someone under its control or in the possession or control of any agent or nominee of the Trustee or any income thereon or as to the preservation of rights against prior parties or any other rights pertaining thereto, except the duty to accord such of the Collateral as may be in its possession substantially the same care as it accords similar assets held for the benefit of third parties;

(c)    the Trustee shall be under no obligation independently to request or examine insurance coverage with respect to any Collateral; and

3

(d)    the Trustee shall be under no obligation or duty to take any action under the Indenture or the Pledge Agreement if taking such action would subject the Trustee to a tax in any jurisdiction where it is not then subject to a tax or would require the Trustee to qualify to do business in any jurisdiction where it is not then so qualified.

Section 6.04. R elease of Collateral .

(a)    Each of the Holders irrevocably authorizes the Trustee to release any lien on the Collateral and/or to terminate the Pledge Agreement (i) upon the satisfaction and discharge of the Indenture Obligations or (ii) if consented to by the Holders of each Outstanding Note.

(b)    In no event shall the Trustee be obligated to execute or deliver any document evidencing any release or re-conveyance of Collateral without receipt of an Officer’s Certificate and an Opinion of Counsel, each stating that all conditions precedent provided for in the Indenture and the Pledge Agreement relating to such release or re-conveyance have been complied with and that such release or re-conveyance of the Collateral is authorized or permitted by the terms of the Indenture and the Pledge Agreement.

ARTICLE VII

MISCELLANEOUS

Section 7.01. Ratification of Indenture . This Third Supplemental Indenture is executed and shall be constructed as an indenture supplement to the Base Indenture, as amended and supplemented by the Second Supplemental Indenture and as further supplemented and modified hereby, the Base Indenture and the Second Supplemental Indenture are in all respects ratified and confirmed, and the Base Indenture, the Second Supplemental Indenture and this Third Supplemental Indenture shall be read, taken and constructed as one and the same instrument.

Section 7.02. Trust Indenture Act Controls . If any provision of this Third Supplemental Indenture limits, qualifies or conflicts with another provision that is required or deemed to be included in this Third Supplemental Indenture by the Trust Indenture Act, the required or deemed provision shall control.

Section 7.03. Notices . All notices and other communications shall be given as provided in the Indenture.

Section 7.04. Governing Law . THIS THIRD SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK APPLICABLE TO AGREEMENTS MADE OR INSTRUMENTS ENTERED INTO AND, IN EACH CASE, PERFORMED IN THE STATE OF NEW YORK.

Section 7.05. Successors . All covenants and agreements in this Third Supplemental Indenture by the Company shall bind its successors and assigns, whether so expressed or not.

Section 7.06. Counterparts . This Third Supplemental Indenture may be executed in several counterparts, each of which shall be an original and all of which shall constitute but one and the same instrument. Counterparts may be executed either in original, facsimile or electronic (i.e., “pdf” or “tif”) form and the parties hereto adopt any signatures received by facsimile or electronic (i.e., “pdf” or “tif”) transmission as the original signature of such party.

4

Section 7.07. Headings . The Article and Section headings of this Third Supplemental Indenture are for convenience only and shall not affect the construction hereof.

Section 7.08. Trustee Not Responsible for Recitals . The recitals contained herein shall be taken as the statements of the Company and the Guarantors and the Trustee assumes no responsibility for their correctness. The Trustee makes no representations as to the validity or sufficiency of this Third Supplemental Indenture, except that the Trustee represents that it is duly authorized under its corporate bylaws to execute and deliver this Third Supplemental Indenture and perform its obligations hereunder.

5

IN WITNESS WHEREOF, the parties have caused this Third Supplemental Indenture to be duly executed as of the date first written above.

Signature page to Third Supplemental Indenture

Signature page to Third Supplemental Indenture

Signature page to Third Supplemental Indenture

Signature page to Third Supplemental Indenture

Exhibit 4.2

EXECUTION VERSION

PLEDGE AGREEMENT

This PLEDGE AGREEMENT, dated as of February 22, 2018 (as amended, amended and restated, supplemented or otherwise modified from time to time in accordance with the provisions hereof, this “ Agreement ”) made by and between SEASPAN CORPORATION (together with any successor, the “ Grantor ”), as grantor, pledgor, assignor and debtor, in favor THE BANK OF NEW YORK MELLON, in its capacity as trustee (the “ Trustee ”) pursuant to the Indenture, dated as of October 10, 2017 (the “ Base Indenture ”), by and between the Grantor and The Bank of New York Mellon, as trustee (the “ Trustee ”), as amended and supplemented by a second supplemental indenture (the “ Second Supplemental Indenture ”), dated as of February 14, 2018, by and among the Grantor, certain subsidiary guarantors specified therein (the “ Guarantors ”) and the Trustee, as further amended and supplemented by a third supplemental indenture, dated as of February 22, 2018 (the “ Third Supplemental Indenture ” and, collectively with the Base Indenture and the Second Supplemental Indenture, the “ Indenture ”), by and among the Grantor, the Guarantors and the Trustee.

NOW THEREFORE, in consideration of the foregoing premises and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Grantor and the Trustee hereby agree as follows:

Section 1.01      Definitions . The following terms shall have the following meanings:

“ Secured Obligations ” means the Indenture Obligations (as defined in the Second Supplemental Indenture).

“ Secured Parties ” means, collectively, the Trustee and the Holders (as defined in the Second Supplemental Indenture).

“ Shares ” means 100 shares of the capital stock, par value $0.01 per share, of Seaspan Investment I Ltd. owned by the Grantor and evidenced by certificate number 001.

Any capitalized terms used but not otherwise defined herein shall have the meanings assigned to such terms in the Indenture.

Section 1.02      Pledge .

(a)    As collateral security for the payment and performance in full of all the Secured Obligations, the Grantor hereby pledges, assigns and grants to the Trustee for the ratable benefit of the Secured Parties, a lien on and security interest in and to all of the right, title and interest of such Grantor in, to and under the following property, wherever located, and whether now existing or hereafter arising or acquired from time to time: (i) the Shares; and (ii) to the extent not covered by clause (i) of this sentence, all proceeds and products of the foregoing, all books and records at any time evidencing or relating to the foregoing, all supporting obligations related thereto, and all accessions to, substitutions and replacements for, and profits and products of, the foregoing, and any and all proceeds of any indemnity, warranty or guaranty payable to the Grantor from time to time with respect to the foregoing.

(b)    Upon the occurrence and during the continuance of an Event of Default under the Indenture, the Trustee shall have the right to receive all distributions, fees, compensation and other monies constituting or payable with respect to the Shares and the same and the proceeds thereof shall be applied, along with other stated payments due under the Indenture, to the Secured Obligations in accordance with the Indenture until the Secured Obligations shall have been repaid in full.

(c)    Upon the occurrence and during the continuation of an Event of Default under the Indenture, following written notice by the Trustee (acting at the written direction of the Holders of not less than a majority in principal amount of the Outstanding Notes) to the Grantor: (i) all rights of the Grantor to receive the dividends, distributions and interest payments which it would otherwise be authorized to receive and retain with respect to the Shares shall cease and all such rights shall thereupon be vested in the Trustee which shall then have the sole right to receive and hold such dividends, distributions and interest payments; and (ii) all dividends, distributions and interest payments which are received by the Grantor contrary to the provisions of the foregoing clause (i) shall be received in trust for the benefit of the Trustee, shall be segregated from other property or funds of the Grantor, and shall be forthwith paid over to the Trustee in the exact form received, to be held by the Trustee as further collateral security for the Secured Obligations.

(d)    Upon the occurrence and during the continuance of an Event of Default under the Indenture, and following written notice by the Trustee (acting at the written direction of the Holders of not less than a majority in principal amount of the Outstanding Notes) to the Grantor, all rights of the Grantor to exercise the voting and other consensual rights which it would otherwise be entitled to exercise with respect to the Shares shall cease and all such rights shall thereupon become vested in the Trustee which shall then have the sole right to exercise such voting and other consensual rights. Notwithstanding any other provision of this Agreement, the Trustee shall not be deemed to assume any contractual obligation of the Grantor owing to any Person by reason of this Agreement or a foreclosure by the Trustee on the Shares, and such obligations shall remain the obligations of the Grantor.

(e)    The Trustee shall not be obligated to perform or discharge, nor does it hereby undertake to perform or discharge, any obligation, duty or liability imposed on the Grantor under or by reason of any organizational document of the Grantor or Seaspan Investment I Ltd., and the Grantor does hereby agree to indemnify the Trustee for and to hold the Trustee harmless of and from any and all liability, loss, damage, tax, judgment, suit, penalty, cost, or expense (including, without limitation, fees, costs and expenses of any counsel, experts and agents) which it may or might incur as a result of this Agreement or any such obligation, duty or liability or any action or claim relating thereto.

Section 1.03      Representations and Warranties . The Grantor represents and warrants as follows:

(a)     Ownership of Property and No Other Liens . The Grantor is the sole, direct, legal and beneficial owner of the Shares, and has good and marketable title to the Shares, and the Shares are not subject to any lien, claim, option or right of others.

(b)     Perfected Security Interest .  This Agreement is effective to create in favor of the Trustee for the ratable benefit of the Secured Parties, a legal, valid and enforceable security interest in the Shares.

Section 1.04      Modification in Writing . None of the terms or provisions of this Agreement may be amended, modified, supplemented, terminated or waived, and no consent to any departure by the Grantor therefrom shall be effective, except by a written instrument signed by the Trustee and the Grantor in accordance with the terms of the Indenture.

2

Section 1.05      Governing Law . This Agreement and any claim, controversy, dispute or cause of action (whether in contract or tort or otherwise) based upon, arising out of or relating to this Agreement and the transactions contemplated hereby shall be governed by, and construed in accordance with, the laws of the State of New York.

Section 1.06      Counterparts . This Agreement and any amendments, waivers, consents or supplements hereto may be executed in counterparts (and by different parties hereto in different counterparts), each of which shall constitute an original, but all taken together shall constitute a single contract. Delivery of an executed counterpart of a signature page to this Agreement by facsimile or in electronic (i.e., “pdf” or “tif”) format shall be effective as delivery of a manually executed counterpart of this Agreement.

Section 1.07      Trustee Rights . The Trustee shall be entitled to the same rights, protections, immunities and indemnities as set forth in the Indenture, as if the provisions setting forth those rights, protections, immunities and indemnities are fully set forth herein.

Section 1.08      Termination . The lien and security interest granted hereunder shall terminate and be released, in whole or in part, as provided in Section 6.04 of the Third Supplemental Indenture. Additionally, this Agreement shall terminate as provided in Section 6.04 of the Third Supplemental Indenture. In connection with any termination or release pursuant to this Section 1.08, the Trustee shall, subject to its receipt of any documents required to be delivered to it under the Indenture, execute and deliver to the Grantor or authorize the filing of, at the Grantor’s expense, all documents that the Grantor shall reasonably request and that are necessary to evidence such termination or release in form and substance reasonably satisfactory to the Trustee. Any execution and delivery of documents pursuant to this Section 1.08 shall be without recourse to or warranty by the Trustee.

Section 1.09      Successors and Assigns . All of the terms, covenants, warranties and conditions contained in this Agreement shall be binding upon and inure to the benefit of the parties hereto and their respective successors and assigns; provided , however , that the Grantor may not assign any of its indebtedness, liabilities or obligations hereunder.

Section 1.10      Notices . Any notice or request hereunder may be given to the Grantor or the Trustee in accordance with Section 1.5 of the Base Indenture.

Section 1.11      Further Assurances . The Grantor agrees that at any time and from time to time, upon the written request of the Trustee (acting at the written direction of the Holders of not less than a majority in principal amount of the Outstanding Notes), the Grantor will execute and deliver such further documents and do such further acts and things as the Trustee may reasonably request in order to effect the purposes of this Agreement and to protect and perfect the security interests granted hereunder.

[SIGNATURE PAGE FOLLOWS]

3

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be executed as of the date first written above by their respective officers thereunto duly authorized.

[Pledge Agreement Signature Page]