clearance diver

A clearance diver was originally a specialist naval diver who used explosives underwater to remove obstructions to make harbours and shipping channels safe to navigate, but the term "clearance diver" was later used to include other naval underwater work. Units of clearance divers were first formed during and after World War II to clear ports and harbours in the Mediterranean and Northern Europe of unexploded ordnance and shipwrecks and booby traps laid by the Germans.