[pmulcahy11b]

I only have very basic explosives training, but I do know that the task the player's tried can be done -- explosives can be set and detonated underwater. (Just ask the crew of the Rainbow Warrior.) I believe you need special wiring and blasting caps, but you could logically assume that these are in the basic demolitions kit in T2K. The person directing the setting of the charges also might need special training to make the explosives go off just the right way to do what the players want to do -- I know I'd have no idea of how to do it.