HORNBECK OFFSHORE SERVICES, INC. and the Guarantors named herein Series A and Series B 5.875% Senior Notes due 2020 THIRD SUPPLEMENTAL INDENTURE Dated as of July 12, 2019 ____________________ WILMINGTON TRUST, NATIONAL ASSOCIATION Trustee

Exhibit 4.28

XXXXXXXX OFFSHORE SERVICES, INC. and
the Guarantors named herein
Series A and Series B
5.875% Senior Notes due 2020 THIRD SUPPLEMENTAL INDENTURE Dated as of July 12, 2019
____________________ WILMINGTON TRUST, NATIONAL ASSOCIATION
Trustee

This THIRD SUPPLEMENTAL INDENTURE, dated as of July 12, 2019, is among Xxxxxxxx Offshore Services, Inc., a Delaware corporation (the "Company"), each of the parties identified under the caption "Guarantors" on the signature page hereto, including Xxxxxxxx Offshore Navegacao Ltda, a Brazilian Limitada (“HON”) and Xxxxxxxx Offshore Services de Mexico, S. de X.X. de C.V., a Mexican Sociedad De Responsabilidad Limitada De Capital Variable (“HOSMEX”) (collectively, the "Guarantors") and Wilmington Trust, National Association, a national banking association, as Trustee.

RECITALS

WHEREAS, the Company, certain Guarantors and the Trustee entered into an Indenture, dated as of March 16, 2012 (the "Indenture"), pursuant to which the Company has originally issued $375,000,000 in principal amount of 5.875% Senior Notes due 2020 (the "Notes"); and

WHEREAS, Section 9.01 (f) of the Indenture provides that the Company, the Guarantors and the Trustee may amend or supplement the Indenture in order to add any new Guarantor to comply with Section 10.02 or 10.03 thereof, without the consent of the Holders of the Notes; and

WHEREAS, each of HON and HOSMEX has guaranteed certain indebtedness of the Company and, by so doing, is required pursuant to Sections 4.13 and 10.02 of the Indenture to execute this Supplemental Indenture and a notation of guarantee of Notes; and

WHEREAS, all acts and things prescribed by the Indenture, by law and by the charter and the bylaws (or comparable constituent documents) of the Company, of the Guarantors and of the Trustee necessary to make this Supplemental Indenture a valid instrument legally binding on the Company, the Guarantors and the Trustee, in accordance with its terms, have been duly done and performed;

NOW, THEREFORE, to comply with the provisions of the Indenture and in consideration of the above premises, the Company, the Guarantors and the Trustee covenant and agree for the equal and proportionate benefit of the respective Holders of the Notes as follows:

ARTICLE 1

SECTION 1.01. This Supplemental Indenture is supplemental to the Indenture and does and shall be deemed to form a part of, and shall be construed in connection with and as part of, the Indenture for any and all purposes.

SECTION 1.02. This Supplemental Indenture shall become effective immediately upon its execution and delivery by each of the Company, the Guarantors and the Trustee.

ARTICLE 2

From this date, in accordance with Section 10.02 or 10.03 and by executing this Supplemental Indenture and the accompanying notation of Subsidiary Guarantee (a copy of which is attached

hereto), the Guarantors whose signatures appear below are subject to the provisions of the Indenture to the extent provided for in Article 10 thereunder.

ARTICLE 3

SECTION 3.01. Except as specifically modified herein, the Indenture and the Notes are in all respects ratified and confirmed (mutatis mutandis) and shall remain in full force and effect in accordance with their terms with all capitalized terms used herein without definition having the same respective meanings ascribed to them as in the Indenture.

SECTION 3.02. Except as otherwise expressly provided herein, no duties, responsibilities or liabilities are assumed, or shall be construed to be assumed, by the Trustee by reason of this Supplemental Indenture. This Supplemental Indenture is executed and accepted by the Trustee subject to all the terms and conditions set forth in the Indenture with the same force and effect as if those terms and conditions were repeated at length herein and made applicable to the Trustee with respect hereto.

SECTION 3.03. THE LAW OF THE STATE OF NEW YORK SHALL GOVERN AND BE USED TO CONSTRUE AND ENFORCE THIS SUPPLEMENTAL INDENTURE.

SECTION 3.04. The parties may sign any number of copies of this Supplemental Indenture. Each signed copy shall be an original, but all of such executed copies together shall represent the same agreement. The exchange of copies of this Supplemental Indenture and of signature pages by facsimile or PDF transmission shall constitute effective execution and delivery of this Supplemental Indenture as to the parties hereto and may be used in lieu of the original Supplemental Indenture for all purposes. Signatures of the parties hereto transmitted by facsimile or PDF shall be deemed to be their original signatures for all purposes.

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

COMPANY:

XXXXXXXX OFFSHORE SERVICES, INC.

By	/s/ Xxxxx X. Xxxx, Xx.
Name:	Xxxxx X. Xxxx, Xx.
Title:	Executive Vice President and Chief Financial Officer

GUARANTORS:

ENERGY SERVICES PUERTO RICO, LLC

XXXXXXXX OFFSHORE SERVICES, LLC

XXXXXXXX OFFSHORE TRANSPORTATION, LLC

XXXXXXXX OFFSHORE OPERATORS, LLC

HOS-IV, LLC

XXXXXXXX OFFSHORE TRINIDAD & TOBAGO, LLC

HOS PORT, LLC

XXXXXXXX OFFSHORE INTERNATIONAL, LLC

HOI HOLDING, LLC

HOS HOLDING, LLC

By	/s/ Xxxxx X. Xxxx, Xx.
Name:	Xxxxx X. Xxxx, Xx.
Title:	Executive Vice President and Chief Financial Officer

XXXXXXXX OFFSHORE NAVEGACAO LTDA

By	/s/ Xxxxxx X. Xxxx
Name:	Xxxxxx X. Xxxx
Title:	Associate Director

XXXXXXXX OFFSHORE SERVICES DE MEXICO, S. DE X.X. DE C.V.

By	/s/ Xxxxxx X. Xxxxxxx
Name:	Xxxxxx X. Xxxxxxx
Title:	Vice President

TRUSTEE:

WILMINGTON TRUST, NATIONAL ASSOCIATION,
as Trustee

By	/s/ Xxxxx Xxxxxx
Name:	Xxxxx Xxxxxx
Title:	Vice President