Caye Caulker is a small island that lies just inside the barrier reef. It's popular with visitors to Belize, but to call it a resort island would give the wrong impression: The atmosphere is very slow paced—Ambergris Caye seems almost like a metropolis by comparison—and Caulker's official motto, seen on signs around the island, is actually "Go Slow." The only transportation available on the island is golf carts and bicycles.
Some development has taken place—some slightly more elaborate inns, a few condos, a small airport—but the islanders seem intent on keeping things in check. Life is simple for both residents and guests on Caye Caulker, and it's a great destination for anyone who wants a totally relaxed vacation at budget prices, though its popularity is slowly but surely growing.
Snorkeling and diving are the main activities, as the barrier reef is only a five-minute boat ride away. Frenchie's Diving is well established in the area, and offers half-day, full-day and overnight trips. https://www.frenchiesdivingbelize.com.
Fishing excursions can also be arranged. The island still doesn't have much of a beach, despite recent efforts to expand it on the Caribbean side. Most of the sunning and swimming is done off the docks or at the Split, a hurricane-carved channel at the north end of the island. Be careful if you go swimming there: Boats use the channel on occasion. Part of the northern section of the island is a marine reserve and national park.
Visitors stay on the southern end of the island, where there are more than 50 guesthouses, inns and small hotels (from inexpensive to moderately priced). Water taxis travel the 20 mi/30 km distance from Belize City to the caye in about 45 minutes for about BZ$35 one way. Commuter flights also connect it to the mainland.