Hornbeck Offshore Operators LLC, Covington, Louisiana (N6238715C2507), is being awarded a $44,974,929 modification for the fixed-price portion of a previously awarded firm-fixed-price contract to exercise a one-year option period (P00115) for the operation and maintenance of four modified off-shore supply vessels USNS Arrowhead (T-AGSE 4), USNS Eagleview (T-AGSE 3), USNS Westwind (T-AGSE 2), and USNS Black Powder (T-AGSE 1), for continued service as support vessels in support of Navy operations. The contract includes a 215-day base period, nine one-year option periods, and one 150-day option period. Work for this option period will be performed at sea worldwide, and is expected to be completed by Sept. 30, 2024. This contract includes nine 12-month option periods and one 150-day option period, which, if exercised, would bring the cumulative value of this contract to $436,969,566. Working capital funds (Navy) in the amount of $44,974,929 are obligated for fiscal 2024, and will not expire at the end of the fiscal year. This contract was issued on a basis of other than full and open competition in support of the statute under provisions of 10 U.S. Code 2304(c)(1), as implemented by Federal Acquisition Regulation 6.302-1, only one responsible source and no other supplies or services will satisfy agency requirements. Military Sealift Command, Norfolk, Virginia, is the contracting activity (N6238715C2507).