Service with the U.S. Army She set sail for the gulf on 23 May 1846 in company with another cutter,
USRC Ewing, and arrived at
Southwest Pass of the
Mississippi River on 19 June 1846. There, General
Zachary Taylor ordered the ship to blockade a stretch of the Mexican coast near
Soto la Marina and capture any ships engaged in trade with the enemy. The squadron that
Forward was assigned to perform scouting, convoy, towing, and blockade duties as well transporting troops and supplies for the Army and occupied her during mid-summer 1846. In mid-October 1846, she joined a force commanded by Commodore
Matthew Calbraith Perry, U.S. Navy. On 15 October 1846, Perry's squadron attempted to cross the bar at the mouth of the river at
Alvarado. The steamer led the way and succeeded in making her crossing,
Forward followed, in tow of sister
revenue cutter, .
McLane grounded on the bar while the three ships she towed fouled each other's towlines.
Vixen engaged the Mexican batteries on shore but, when it became apparent that
McLane would never succeed in getting across the bar, she and her tows retired. Luckily,
McLane came off the bar, and all American ships retired. On 16 October
Forward set sail for a similar, but far more successful, amphibious operation at the mouth of the Tabasco River. Successfully navigating the bar on 23 October 1846, the force quickly seized the town of
Frontera and took several prizes in the process.
Forward and the other small steamers attached to Perry's force then continued the foray, sailing up the river through hostile territory to the town of Tabasco.
Forward supplied part of her crew as a landing party along with Marines that were from USS
Vixen and they captured the town of Tabasco. The flotilla seized 10 vessels as prizes before returning to the ocean on 26 October 1846. However,
Forward along with
McLane remained at Frontera until late November 1846, engaged in the destruction of the captured Mexican shipping and maintaining a blockade of the river. She departed the area on 21 November 1846 and returned to the base at Anton Lizardo on 21 November 1846. In December 1846,
Forward left the Mexican coast to carry dispatches to
Belize City in
British Honduras and
New Orleans, Louisiana. Repairs completed in the summer of 1847 after reaching Wilmington cost about 2,500.
Forward received a commendation from Commodore Perry for her participation in the Tabasco River landings, where-in he said in part: ==Transfer to the U.S. Coast Survey==