UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K/A

Amendment No. 1

For the fiscal year ended December 31, 2011

or

For the transition period from            to            .

Commission File Number 333-165796

UNITED MARITIME GROUP, LLC

(Exact name of registrant as specified in its charter)

601 S. Harbour Island Blvd., Suite 230

Tampa, FL 33602

(Address of principal executive offices)

(813) 209-4200

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

None

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ¨     No   x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes  ¨     No  x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports) and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.    x

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

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

The registrant is a wholly-owned subsidiary of GS Maritime Intermediate Holding LLC (“Intermediate Holding Company”), which is a wholly-owned subsidiary of GS Maritime Holding LLC (the “Holding Company”). As of December 31, 2011, there were 100,491 membership units of the Holding Company outstanding. There is no trading market for the membership units of the Holding Company, Intermediate Holding Company or the registrant.

EXPLANATORY NOTE

The sole purpose of this Amendment No. 1 to the Annual Report on Form 10-K for the fiscal year ended December 31, 2011 of United Maritime Group, LLC (the “Company”) filed with the Securities and Exchange Commission on March 30, 2012 (the “Form 10-K”) is to update Exhibit 101 to the Form 10-K. The version of Exhibit 101 originally furnished with the Form 10-K was incorrect due to a filing error by the Company’s financial printer.

No other changes have been made to the Form 10-K. This Amendment No. 1 to the Form 10-K speaks as of the original filing date of the Form 10-K, does not reflect events that may have occurred subsequent to the original filing date, and does not modify or update in any way disclosures made in the original Form 10-K (other than Exhibit 101).

PART IV

The following documents are filed as part of this Report:

See Item 8, “Financial Statements and Supplementary Data.”

N/A

The exhibits required to be filed by Item 601 of Regulation S-K are listed in the Exhibit Index, which is attached hereto, and incorporated by reference herein.

Exhibits and Financial Statement Schedules

(a) (b) (c) (d) (e) Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, United Maritime Group, LLC has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: April 23, 2012