In June 1898 Spanish Navy ships sank her when she tried to trap them in the harbor of Santiago de Cuba.

CS Swan & Hunter built the ship in Wallsend on the River Tyne as yard number 194.

Ownership then passed to a Jefferson T Hogan, who on 12 April 1898 sold Merrimac to the United States Navy.

[3] A young Lieutenant, Richmond P. Hobson, devised a plan to scuttle Merrimac as a blockship to trap Spanish warships that were thought to be in Santiago harbor.

Ten improvised torpedoes were hung under her hull, to be electrically detonated simultaneously once Merrimac was in the correct position.

[7] A launch from USS New York accompanied Merrimac as far as the harbor mouth, where it was to wait to pick up Hobson and his crew from the dinghy.

But Spanish coastal artillery howitzers opened fire, and a shell disabled Merrimac's steering gear, which prevented Hobson and his crew from swinging her into position.

A Spanish submarine mine tore a hole in her side, and she grounded on a promontory called Estrella Point.

[16] A month later, on 3 July 1898, the US Navy destroyed the Spanish fleet in the Battle of Santiago de Cuba.