I swam off of Cape Cod (in season) for most of my youth. When I was young & fearless (reckless), I used to catch small sand sharks with my bare hands, just for the fun of it. Other than that, I didn't see a whole lot of sharks in the area, except for when that one shark tournament happened in the middle of the summer. Most of those sharks were picked up from the trench between the islands to the south, with a smaller percentage coming in from locations off the mainland. I never worried about sharks for the 20+ years that I swam in that area, even when I went to the same beach where Jaws was filmed.
Here in Florida, I see A LOT more sharks. Mostly, I see bull sharks. Second most common is probably spinners. Hammers are not uncommon. Fine Tooth, Sharp Nose, Sand Bar & a few others show up on occasion. We also have big Cudas, Wahoo & smoker size Kingfish here that can remove fingers or hands if you are not careful. Around here, when you reel in a fish head nstead of a whole fish, we just consider it akin to paying the tax man.
Gators are plentiful in this state. We also have a few salt water crocks in some places. The crocks are much more aggressive, but a calm-seeming gator did get a friend's golden retriever a couple of years ago. Out in the glades, I have seen black panthers. We also have some fairly gigantic snakes. In this state, it is legal to open carry a handgun without a permit when fishing. There is a reason for that. In some places around here, it's a good idea. Offshore, I don't feel the need.
Yea, we have a fair selection of dangerous critters here in the sunshine state. They are more numerous than what I used to see in the NE, but not as numerous as the ones that I used to see when I lived in AZ. I personally haven't had any problems in any of these locations.