View Full Version : Long time immersion in water (Diving)

02-13-2013, 06:58 AM
I'm a recreational diver but this is beyond my knowledge base.

The character, let's say a former SEAL and still active, will enter the water in a slow moving piece of river. He'll hide, submerged, for 8-10 hours in water that is probably 65-70 degrees and very murky. After that he nearly surfaces to attach explosives to the hull of a boat. Given the target is is reasonable to think that other divers would search the hull an hour or so before a VIP is scheduled to arrive. He'll have to come out of hiding after the search and place his explosives, then hide again for another 2-3 hours.

I'm thinking a dry suit would be required. We can assume earlier access to the area and that he would have been able to secure multiple tanks to one of the dock's support posts. We will also assume a good rebreather to reduce bubbles.

My questions relate to impact of gas build-up after 8-10 hours at 25-30 feet, a brief climb to just below the surface (3 -6 feet), then going back to 25-30 for a couple of hours.

Beyond that, would the motion of a propelsion aid at 20 feet in murky water with a modest current cause any ripples that might be seen by security people?