Well, in a similar boat sinking vein, I was once doing a very late afternoon / very
very late 'summer' dive in the Baltic Sea off Finland back in mid 90's, off a small private 'cabin-cruiser' boat with about four divers aboard. I was first in the water and was told to go wait at the surface on the anchor line. After a short time I heard
very loud voices speaking
excitedly in Finnish - which I did not understand - coming from astern, but just from the tone I could tell something was
very wrong! Sure enough, in no time at all, the others where in the water (without their cylinders on) and the boat had sunk stern first leaving, thankfully, just the tip (of the air filled bow) sticking out of the water for us to gather around. Luckily a Mayday had been sent just prior to their abandonment, and we spent what seemed like an eternity, but was probably about two hours maybe, but well after dark, before the coast guard arrived. Needless to say, we all had drysuits on so did not suffer too much. Lost a bit of kit, but nothing irreplaceable.
The cause of the accident? The boat had just been serviced and prop shaft replaced and.................a stuffing gland left out / or 'unstuffed', and this was the first time the boat was back in water post service. So, as long as we were mobile at speed, no or little water ingressed, but while we geared up after stopping it certainly did, and.................well, another adventure for the log book.
PS. Chairman, I have not forgotten you request re 'course details' but as I said, its going to take a bit to dredge all those pretty much forgotten details out of the old memory banks. But some instances, like the one above, the death of the guy on the RJB & CC, the cave dive alluded to in an earlier post, and beating, literally, circling sharks away - with a u/w camera housing - whilst at the surface waiting for the pickup boat after a dive on the outer GBR definitely gets ones attention, and
forever sticks in ones mind.