Thinking from a passenger point of view, if I was on a ship/oil rig which was on fire/sinking, I am not going to wait for Crab or anyone else to rock up with a helicopter or Thunderbird 2, winch or basket. Straight for the lifeboats/liferafts. There is no way that helicopters are the answer to quickly evacuating large passenger vessels/oil rigs unless they can land on and there are lots of them.