Depth charges used by the Grand Army of the Republic.
Depth charges were underwater warfare weapons intended to damage or destroy submarine vehicles and troops. They exploded upon contact.
During the Invasion of Naboo in 32 BBY,[1] the B1 battle droid OOM-9 ordered depth charges placed in Lake Paonga to flush out the Gungans from the underwater city Otoh Gunga.[2]
The Grand Army of the Republic used depth charges against Separatist underwater forces during the Battle of Mon Calamari.