I wouldn''t worry too much about sharks if I were you. I used to work on a shark fishing boat off Florida. Most of the species tend to hang out fairly deep. And for the most part, they''re not really interested in eating people. I guess we taste funny! However, there are some precautions that it is reasonable to take. Don''t swim with schools of baitfish. Don''t swim if you''ve been fishing and have dumped fish guts over. Don''t swim if you''re leaking blood from a cut.
And keep in mind that decades of overfishing have really decimated the shark populations. There really aren''t too many left out there. More sailors are hurt by overused liquor lockers than by sharks.