My wife and I have been snorkeling in the Florida Middle Keys for about 10 years now. We do go out to the big reef spots once a year or so, but we'd much rather snorkel shallower spots where we can look for things we can't see while snorkeling at deeper and protected reefs. We enjoy finding brittle and serpent sea stars, mantis shrimp, sea cucumbers, coral banded shrimp, lobsters, spaghetti worms, fan worms, several varieties of conch, sand dollars, sea biscuits, all kinds of crabs (big and small), snails, small stony corals, lots of soft corals, flamingo tongue snails and other mollusks. And while in the shallows we've seen squid, octopus (both small and medium sized), rays, sharks, moray eels, barracuda, juvenile tropical fish, a couple of large turtles and more.
We have done a lot of 'off the beach' snorkeling where no boat is required. We've done some near shore islands where a kayak, inflatable or small boat is required. And we have just upgraded our Achilles high pressure air floor and 5hp Honda outboard (now for sale) to a Zodiac rib with a 20hp Suzuki. Now we can start getting a bit further away from the main string of islands.
I'm willing to share locations and reviews of the places we've snorkeled... even google earth maps.
One super easy and very cool location is Bahia Honda State Park. Off the beach on the southwest end of the island (ocean side) has a great assortment of things to see. The water is shallow a long way off shore. At low tide you can easily get close to a 1/4 mile off the beach and still be in just 5' to 8' of water. There are a wide variety of gorgonian corals, some stony corals, occasionally even larger stony corals, many big ball and vase sponges along with tons of very colorful smaller sponges. There are lots of juvenile tropical fish. We've even seen a few moray eels, reef squid, and even a ray or shark on days that the water isn't crowded with snorkelers. Go about halfway between the bath house and the SW end of the island, then go straight out off the beach. By 100' out you will start seeing cool stuff. And the further out you go, the bigger the gorgonians get and the more often you will find uncommon stuff.
The 2 drawbacks to Bahia Honda are it costs money to get in the park and it's protected, so no collecting of any live animals. But you can pick up rocks and look for critter underneath.
We hit 5 spots last trip (June 19th-22nd) and here are a few pics.
Typical of the big reefs, here is one we did on a snorkel charter.
But close to shore we can pick up rocks and find things like these.
Sorry for the blurry pic, but this beautiful coral was just 10 feet off the beach in less than 3' of water.
And not 20' from that coral we found these. I saw the star first and it was really big at 10" or more.
But then I saw something move down at the other end of the rock that I couldn't ID at first. Then it moved over by the star.
It's the first moray eel I've seen completely out of it's hole, and a spotted moray at that!
We regularly visit about 8-10 other sites in the middle keys (near Marathon). I'm willing to share if anybody is interested. And I'd really like to find some spots in the upper and lower keys or islands that are off shore... especially within the range of an 11' Zodiac and a 20hp outboard!