"The Last Dive" is a great book if you want to read up on the accident. As well as can be pieced together, some shelving fell on the son while he was digging around on the floor in the captains cabin on the U-boat. He panicked and started screaming and flailing around and the father went in after him to free him. He did manage to free him but they both lost their bearings in the silt and had trouble getting out. When they did exit it was from another part of the U-boat and they were not able to find their way back to the original entrance where the stage bottles with the deco gas were located. They started deco with what they had left but then had a regulator problem and the dad went to the surface to arrange for more gas. The son however quickly followed and both were badly bent by the time they surfaced.
The dad died in a very short time and the son survived long enough to make it to a recompression chamber but there was not a lot they could do for him as he was way beyond what could be done in a chamber with a 165' depth capability. (We are talking trying to draw a blood sample and getting nothing but foam.)
The dive was done on air and nitrogen narcosis was definitely a contributing factor to the accident. It was speculated that on the one hand, trimix would have helped both in the U-boat and again once outside in finding their way back to the stage bottles. On the other hand the higher gas consumption associated with trimix may have resulted in them running out of gas in the U-boat. Who knows. It was however a very aggressive penetration and a very dangerous dive under any circumstance.
The dad died in a very short time and the son survived long enough to make it to a recompression chamber but there was not a lot they could do for him as he was way beyond what could be done in a chamber with a 165' depth capability. (We are talking trying to draw a blood sample and getting nothing but foam.)
The dive was done on air and nitrogen narcosis was definitely a contributing factor to the accident. It was speculated that on the one hand, trimix would have helped both in the U-boat and again once outside in finding their way back to the stage bottles. On the other hand the higher gas consumption associated with trimix may have resulted in them running out of gas in the U-boat. Who knows. It was however a very aggressive penetration and a very dangerous dive under any circumstance.