Humph!! DS Zachary is sitting on my lap and just announced he doesn't want to go on the cruise. When I asked him why, he said, "Because I think a shark will get me!"
Take him to the Milwaukee Zoo, he can actually pet a shark there.
DS had a zoo class there the other week with Sharks and Rays. He was all excited that he got within a foot of the shark. Granted they are little ones and not a great white.