Hol Chan & Shark Ray Alley are to the south & are usually combined into one trip, Mexico Rocks is to the north of town & is usually a separate trip.There are some operators who will combine all three in one day.
A couple others are Robles Point and Basil Jones.
Hol Chan can get a bit crowded, I prefer Mexico Rocks, you may not see as much fish as Hol Chan, but the coral is beautiful.
There are many good operators, I use Amigos Del Mar & they will pick you up & drop you off at your dock as most operators will.
Do a 1/2 day trip to Caye Caulker ,It's only a 20 min. water taxi ride inside the reef.
I would think there would be some good snorkeling there. Have a great trip!!!