There’s no shortage of guide services in Placencia , where most tour operators offer service to all nearby destinations: Cockscomb Basin Wildlife Sanctuary , Monkey River , snorkeling and fishing trips  with lunch on a beautiful caye, the Maya ruins of Lubaantun  and Nim Li Punit , and a variety of paddling tours .
Many tour operators have their offices/shacks clustered by the main dock in town, just past the gas station; most are subcontracted by the hotels that offer tours to their guests. If you’re going it on your own, ask around and know that prices often rely on a minimum number of passengers, usually four. Prices vary little, but it’s definitely worth comparing. Monkey River day trips, for example, range US$40–60 per person, depending on whether lunch is included and the size of the boat. Half-day snorkel trips are about US$35–50 per person. Most tours require that you sign up the day before; reef tours typically leave around 9 a.m. and inland tours around 7 a.m.
Seahorse Dive Shop (tel. 501/523-3166, www.belizescuba.com ), by the gas station, is highly recommended for whale shark tours.
Right by the main dock, Nite Wind (tel. 501/523-3487, renidrag_99 [at] yahoo [dot] com) is very reliable. Just up the sidewalk you’ll find Ocean Motion (www.oceanmotionplacencia.com , tel. 501/523-3363 or 501/523-3162) and Placencia Dive School (tel. 501/628-0911).
Hubert and Karen Young’s Joy Tours (tel. 501/523-3325, www.belizewithjoy.com ) is next to Tim’s Chinese restaurant. There are also some individual guide gurus lurking around town; ask around your hotel or at restaurants.