Hi, and I'm sorry for taking so long to reply, but I'm way busier now that I'm retired than I ever was when I worked!
Yes and no, I mean the SW end on the ocean side from 100 yards to 300 yards up the beach from the old Flagler RR bridge. Here is a map. If you use Google Earth you can get a very good view.
The beach and very near shore is mostly sand and a few rocky areas. Out at the edge of the very low tide waterline is where turtle grass and some other things grow. Another 50 feet out, about 2' to 3' deep the grasses pretty much go away and you start to see gorgonians, macro algae, lots of sponges (big and small) and lots of other sea life. We have been out as much as 400 yards off the beach and the water was 4' to 8' deep and the gorgonians and sponges get much bigger and the area is much less 'disturbed' by the snorkelers who stay in the shallows.
If seeing sea life other than corals is something you might enjoy, try the next island SW from Bahia Honda. As soon as you are off the bridge there is a turn off to the right (bay side or nw). It ends in a small parking lot and a large path that goes out to an old quarry. It's commonly known as the 'Horseshoe' by the snorkelers in our aquarium club.
Inside it's 40" or more deep, but outside the quarry arms it's shallow and there is a huge variety of eco systems from sandy flats near shore on the SW, very shallow grassy flats out further, good current flow out at the ends of the quarry arms makes great habitat for anemones, crabs, sea cucumbers, sea stars, shrimp, clams, feather dusters, spaghetti worms, and tropical fish. Around from there, to the NE corner of the quarry and you get into slightly deeper water grass flats and if you go parallel to shore but away from the quarry there are shallows that are covered with stony corals, small sponges of every type and lots of other small critters including some zoas and palys. If you dare to get out along the boat channel (a diver down flag is an absolute must at the Horseshoe) there are lobsters, banned coral shrimp, flame scallops, cowries and lionfish. The other advantage to the Horseshoe is that even on windy days, the area is so well protected because of the island shoreline and the quarry arms that stick out in the water, there is always at least some area that is calm enough to snorkel, although visibility may be somewhat reduced due to the stirred up water. Here is a map. The Horseshoe is pretty obvious at the left side, it looks a bit like a swimming pool along the shoreline.
You mentioned trying to come back in August. Weather in the Keys is a bit shaky in August as it's peak hurricane and tropical storm month and therefore even normal summertime afternoon thunderstorms are more frequent and sever (Aug is peak rainfall month). The water is so warm it's like bath water, which is great for extended snorkel times with just a dive skin to protect you from the sun. But Oct and Nov might be much better choices if that is possible. The hurricane and tropical storm threat goes down considerably and the water is still quite warm.
If you'd like to chat more or ask questions, don't try to send me a PM, I'm on probation here... god only knows how long they're going to keep me here. I go to the SWFMAS.com website at least twice a day.