BOSTON — A former U.S. Coast Guard boat that escorted Old Ironsides across Boston Harbor and survived blizzards and nor’easters may have been done in by an extremely low tide.

Chief Paul E. Flanagan told The Boston Herald that the 32-foot Winthrop Fire Boat Sentinel could be totaled. He says the low tide overnight trapped the Sentinel under the town pier, flooding its engine with corrosive salt water.

He says a passer-by saw the Sentinel resting on mud Sunday morning.

The Sentinel was dislodged, pumped out and is back afloat.

Flanagan said the Sentinel participated in search-and-rescue efforts and Massachusetts Port Authority drills. It also was available for use by Homeland Security and Logan International Airport.