It was lost on a test run the same year, and is believed to lie on the seabed of the bay of Valparaiso.

During the test, the submarine sank for unknown reasons; it is now thought to lie at a depth of about 50 meters (164 feet) within the bay of Valparaiso.

The Flach was located two days after the sinking by seamen from the English frigate HMS Leander, and a diver named John Wallace was able to see and draw the wreck, which was buried nose-down in the bay's sediment.

The Chilean Navy, with support from others, has searched for the submarine and intends to raise it after finding it, even though there is as yet no agreement on what to do with the remains of the eleven bodies thought to be inside.

A finding of an object that appears to be the Flach was reported in El Mercurio de Valparaiso on 25 April 2007.