dc_misc:

Far below the surface of the ocean a DSRV moved slowly through the cold, dark waters of the Atlantic. Far above the site the DSRV was moving was the city of Poseidonis. The DSRV was part of a marine archeology expedition that had been searching a little distance away from the Atlantean city, but the DSRV had made its way to the former site of the city.

It collected items it found and put them in a bin to carry to the surface.