Audio problem: When Jason Patric is pursuing Willem Dafoe and firing a shotgun, the gun is a semi-automatic (self-loading) model. However, the sound mix includes the very distinctive noise of a pump-action shotgun being cycled manually before each shot.
Audio problem: When Alex orders that the second anchor be dropped, the 1st officer says "I'm telling you we're still too fast." However, his mouth doesn't move at all. (01:33:30)
Answer: There is no logical reason for it and it is purely for cinematic theatrics. It's a movie myth that cars, boats, etc. immediately explode upon impact. In real life, explosions rarely happen that way.
raywest ★