All this about "yummy" yellow or delicious orange or bitten black is all foolishenss. There are no studies that truly prove sharks will attack yellow suited divers anymore than they might attack a diver in black that looks like a seal. I am sure someone will dig up some obscure artical but there are so few shark attacks on divers that the statistics are essentially meaningless.
On the other hand, jet skis will take your head off and so will motor boats. More than that, black does not mean danger to a boater the way orange or yellow does. It just does not grab attention.
I nearly hit two divers surface swimming myself---they had no flag or I would never have gotten near them but without the flag and dressed all in black the only thing that caught my attention was the white of there wide eyes. I just thought the dark area was a small roller from another passing boat. I had no idea it was two divers. Fortuantely--I pay attention and was able to avoid them with room to spare. But, I am a diver and I recognized them--do you really think another boater would have? Possibly not. Had they been in yellow or pink or orange or chartruse neon green I would have seen them much sooner and most importantly recognized that they were humans and not a small wave or schooling fish or driftwood etc. Of course, it would certainly have helped to have had a flag.
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