ABout a year ago i was wade fishing in East Galveston Bay out of my boat where it was too shallow for me to motor. Me and a friend were about a 1/4 mile from the boat so we both had stringers attached to our wading belts with several fish on them. Coming out of a shallow marsh area I felt a strong tug that threw me on my ass and my wading belt broke and stringer disappeared. About 2 minutes later, while we were heading back to the boat my stringer appeared on land, and feeding on the fish was a 5-6 foot Gator. Scared the hell outta me knowing he was probably following me for a while threw that marsh. As for being in the water offshore, I dont have a problem with it, because once you get about a mile off the beach in Galveston the water is actually clear and you can see around you underwater. During the summer we actually take our Spear-Guns offshore and freedive for Red Snapper and Mahi-Mahi, but its definately not for everyone. Back to the Crocs/Gators. As far as I know there isnt any Saltwater Crocs in the Gulf of Mexico, you have to travel further south towards South America to find them. Gators are mainly found in Bay-Systems (like Galveston) BUT always close to shore.
If you come down to Australia have a swim in Darwin harbour.... you will find both salt water crocs and sharks living there... I used to live in the ocean before youtube, with not a bit of fear but then I started watching shark attacks and I am always worried about what could be out there. Went abalone diving just before Christmas off a small island and had this feeling that somewhere was there the whole time I was doing it.... While there is plenty of sharks, especially great whites down the south where I am, I think South Africa is slightly more dangerous than Australia in terms of shark attacks.
The thing that would cause me sphincter-releasing fear around Darwin harbor would be the Box jellyfish and especially the tiny Irukandji_jellyfish. Those things scare the crap out of me from the other side of the world. Next to them, sharks and salt water crocs are like cute little puppies and kittens.
Yeh just more things to worry about... as a kid the ocean didn't worry me at all. Attacks of any really are quite rare though when you consider how many people enter the water every year. I remember reading more people are killed by falling vending machines than sharks or something like that.