In South Florida sport diving depths, you just don't see dangerous species of sharks in the summer. But when the water gets colder, you might see hammerheads, black tips and reef sharks, but not very often.
I was so elated when I first came to Florida and tasted the salty ocean for the first time. I snorkled off the beach in a massive school of mullet. They formed a tunnel as you kicked along, leaving a space of 3 feet around you. I started seeing large silver sided torpedos streaking through the mullet, and I realized: "Here I am, swimming with a school of baitfish. This is not good!" I later found out that the predators were tarpon and black tip sharks that had herded the mullet into shore and were feeding on them when I decided to go snorkling.
You can see erratic behavior in some sharks here in the winter. I've seen larger hammerheads lolling about on the surface, swimming lazily in straight lines. I have no idea why they do that. On one memorable occasion, I was trolling for King mackeral and saw a large tan colored hammerhead swimming on the surface on a 90 degree intersecting course. I held my course steady, and so did the shark, untill he banged into the side of my boat with his head! It was about 6 foot long. He gave a big swoosh of his tail and went down.
Did "Jaws" affect me? Oh yeah

I don't think I will ever see a great white in Florida, but I know there have been some tigersharks caught. For that reason, I'm uncomfortable in visibility lower than 10 ft, including night dives. Nighttime is the "right time" for lobstering, but I just never got comfortable enough to enjoy it. My reptilian brain tells me that just outside the fan of light, JAWS is there, waiting for the light to dim

If I want those reef-roaches, I'll get them in the daylight or do without

Gunthr