Never while out skiing, mostly because I ride on Lake Erie. ;-)
That said, I have seen hundreds, maybe even thousands if sharks all over the world. I am certified up to a Master Diver as well as a Military Diver.
I have been all over the world and in every case I have see some kind of a shark when I have been in the oceans. Browns, Hammer Heads, a few Great Whites and Tiger sharks.
Never had an issue with them yet. However, I'm not poking them with a stick either,,,
Oh, I did catch a 205 pound Brown Shark while fishing off the back of a Disney Cruise ship. I was going to let it go. But,,,, the ship offered me 1000 dollars for it, refund all money we spent for our trip and gave us 750 dollars worth of casino chips that we had to play, not cash in unless we won money. We ended up winning over a grand using their money.
So now the Brown Shark is mounted on the main entry way if the ship.
I was younger and considerably broker back then. I'd let it go if the same deal was given to me today.