The story reminded me of a guy I met in Tampa / Tarpon years ago. He had been a USCG interdiction diver (I think) and I asked him about some of his wildest experiences. One of them, he said, was being under a ship near the screws when the skipper fired it up and put it into gear. Said his heart pretty much exploded in his chest and he just dove fast and hard. Frankly I don’t know why one would risk a multi-million dollar stash by keeping it “near the rudder.”
They put it their because of your friend’s reaction.