zlacker

There's probably thousands of scuba divers are trained in cold water diving to 300ft/100m depths. That is deep technical diving, but not crazy or stupid deep.

>>lamont+(OP)
(Although it would probably be easier these days to use a pipe bomb and a COTS underwater tethered drone -- depending on what bits of physical evidence you were comfortable leaving behind you could just blow the drone up with it too -- the "hardest" part would probably be dodging the coast guard on the surface)