Depth charge
From Memory Alpha, the free Star Trek reference
A depth charge was a type of underwater weapon, used against submerged vessels like submarines.
On stardate 52179.4 (2375) during Tom Paris's attempt to destroy Monean oxygen refineries on The Waters, a photon torpedo was modified to function as a depth charge and used to disable the Delta Flyer and stop Paris. (VOY: "Thirty Days")
