Fraser's motivation...? (Spoilers)
I enjoyed this - obviously flaws with the science and some of the rationale etcetera, but willing to overlook as it was gripping.
However, I really didn't understand why Fraser suddenly was all for going straight to the surface and forfeiting the gold (and being arrested for murder - hello!?!) I didn't buy he felt guilty because the old beardy guy died, because we had just seen him CRYING WITH JOY as he stared at the gold with childish delight - didn't seem too guilty then. It was literally the scene before. Then suddenly he has a complete change of heart? I figured it might be because he realised the Russians were going to kill him the minute they surfaced? Otherwise... Seemed very out of character.