#1 Lauderdale-by-the-Sea. My husband just did a two-hour dive on the first reef, just south of Anglin Pier. 15 feet depth, some days 40 feet viz, some days 10 or so until you get to the reef. We have kayaked to second reef, at 30 feet depth. Third reef is 60 feet or so depth, more of a boat dive site. Very family-oriented town, lots of mom-and-pop hotels (Eastward Strand Hotel & Suites), nice beach walks and town walks. We don't do nightlife or restaurants, but it's there. Morning dives are better viz and less current. We usually spend July at LBTS. Independence Day fireworks on the beach are fun. Seven or eight entrances from Pine Ave to Palm Ave, bring quarters for the parking or use the computerized meter, no night parking. One more reason to rent a block from the beach, for 24/7 enjoyment.
#2 Blue Heron Bridge. When the surf is rough or the viz low, go north an hour on I-95 to Riviera Beach. Phil Foster Park is off Blue Heron Bridge Ave, at Singer Island. We dove the West Bridge (smaller bridge) during high tide this month. East and West are both good. Know your high tides and stay out of the current until slack tide or you can be swept under the bridge. Fishermen and boats are concerns, especially the shallow boat channel on East Bridge. The area away from the bridges is 15 to 20 feet deep, clear, some boat traffic. Force E a few blocks from Phil Foster Park is a good source, and does two night dives a month. The park, which has a nice playground, restrooms, picnic areas, and security, is open 8 am to sundown. No night diving, except with permits. Weekends are packed, the parking places go fast. We kayaked at John D. MacArthur Park, on the north end of Singer Island. The same road goes to it. Nice old-style Florida fauna and flora, too shallow for diving.
#3 Peanut Island. We take our kayak to Phil Foster Park and paddle over to Peanut Island until high tide. Nice snorkeling, sandy beaches, the JFK bunker (we have not toured it, yet). Lots of sailboats, power boats, kayakers, and a regular shuttle boat that brings visitors. Camping is available, but we haven't found out yet where to park our vehicle overnight. Another thing on our bucket list.
While we are at it, we use Fill Express on Dixie Highway. The website includes a map of the snorkel trail south of Anglin Pier in LBTS, just before getting to the first reef. They also have info about area wrecks and reefs for those who do boat dives.
Enjoy your stay!
Edit -- We saw our first manatees a few years ago at the boardwalk on Peanut Island, then saw them while snorkeling in the lagoon. This year we saw one under the West Bridge. Yesterday I waited for Richard to exit West Bridge when the tide got stronger and saw an eagle ray and a southern stingray. Then when we were washing our gear at the fish rinse station we saw another southern stingray glide past the wall.