Ditchings
All the ditchings I have seen on film or TV have rolled to one side and floated for a while. Think back to that footage of the Hueys ditching beside the aircraft carrier when Saigon was lost. Big splashes as rotors thrashed about, fuselages floated long enough for crews to exit if they were conscious.
Two ditchings around NSW involved a twin and a single, both had the same story, roll onto right side, float, sink.
I have no doubt that HUET courses saved lives in those 2 cases. It is great training for the basic principles, which can then be applied to each situation. Very few helos in Oz have floats, so we can expect them to follow the laws of physics and put the heavy bits (transmission, engine, rotor heads) under the empty light bits (cabin, fuel tank) and thus be upside down.
Helicopters: a triumph of science and technology over common sense..