Although the beach is usually fine for swimming and lounging, you won’t see much with a mask and snorkel except sand, sea grass, a few fish, and other bathers. A short boat ride, however, will bring you to the barrier reef and the kind of underwater viewing you can write home about. Snorkel gear is available for rent everywhere (US$5 per day), and trips to the cayes and reefs cost around US$50 per half-day, depending on distance.
Belize’s famous barrier reef extends past Placencia  and is accessible by boat. There are six dive shops with comparable prices, and you can either let your hotel arrange everything or do it yourself.
Avadon Divers (tel. 501/503-3377, www.avadondiversbelize.com ) is run by a brother and sister team with many years of experience; the Belize Tourism Board awarded Avadon in 2010 as one of the top tour operators. They take care of everything (transfer to and from the dive shop, breakfast, lunch, and gear) so that all you have to worry about is seeing the beautiful marine diversity. Call or check with your hotel for a trip schedule.
Seahorse, located on its own dock by the Shell station (tel. 501/523-3166, seahorse [at] btl [dot] net), is highly recommended for whale shark tours. Splash Dive Center (tel. 501/523-3058, www.splashbelize.com ) has an office at the south end of the sidewalk; their dive center and retail store are on the north end.
Farther north, you’ll find a handful of serious dive operations linked to their respective resorts, with professional shops at Robert’s Grove Beach Resort and Turtle Inn.
An unforgettable, underrated way to explore the near-shore cayes, mangroves, creeks, and rivers is by paddle. Open plastic kayaks are available to guests at most resorts, and many tour operators and dive shops have some for rent as well. Boats are also available for rent at the Sugar Reef Bar and are perfect for putting in and paddling up the lagoon in search of birds, manatees, and dolphins.
If you’re into extended sea-kayaking expeditions, see Dave Vernon at Toadal Adventure (www.toadaladventure.com , tel. 501/523-3207 or 501/600-6044). Dave is one of Belize’s premier naturalists and tour guides, and the opportunity to take a personal paddle trip with him is well worth it. He’ll take you on any of a number of paddling trips, such as an overnight Monkey River  tour, weeklong caye-hopping exploration, or river kayaking through Cockscomb Basin, where you’ll encounter a few rapids and possibly a tapir along the calm stretches of South Stann Creek. He also rents kayaks for US$70 a day, with which you can paddle out to any number of cayes and make your own adventure.
Placencia  has always been a fishing town for sustenance, but with the advent of tourism, it has gained a worldwide reputation for sportfishing. Deep-water possibilities include wahoo, sailfish, marlin, kingfish, and dolphin fish; fly-fishing can hook you a grand slam—bonefish, tarpon, permit, and snook (all catch-and-release).
Fortunately, serious angling means serious local guides, several of whom (like the Godfrey brothers, Earl and Kurt) have been featured on ESPN and in multiple fishing magazines. Hire Earl at Trip’N Travel Southern Guides Fly Fishing and Saltwater Adventures (in the Placencia Office Supply building, tel. 501/523-3205, lgodfrey [at] btl [dot] net).
Most tour operators listed throughout this chapter offer fishing trips, and a few specialize in them, like Kingfisher’s Tarpon Caye Lodge, boasting decades of experience (tel. 501/523-3323 or 501/600-6071, kingfisher [at] btl [dot] net, www.tarponcayelodge.com ). Charlie Leslie Sr., owner and head guide, has a stellar reputation and will take you to a variety of spots, from inshore places that include nearby flats to Tarpon Caye and the remote Ycacos area. Also ask about their island cabanas for rent. Check www.placencia.com  for more options.
Opportunities abound for day trips, sunset cruises, snorkel voyages, and sail charters. Expensive, high-end The Moorings (www.moorings.com , tel. 501/523-3351, U.S. tel. 800/535-7289) has a dock in Placencia for multiple catamaran adventures, based on the lagoon side, north of the airstrip.
Belize Sailing Charters (www.belize  sailing charters.com, tel. 501/523-3138) has bareboat and crewed yacht charters. Just across from town, Placencia Yacht Club (placenciayachtclub.com) is on Placencia Caye, featuring the Tranquilo Restaurant and Bar.
Sign up for a massage or other treatment at The Secret Garden Massage and Day Spa (behind Wallen’s, tel. 501/523-3420, www.secretgardenplacencia.com ), where an hour massage costs US$50 and a special four-hands treatment a bit more. If you need relief from the sun and barefooting on the beach, try the sunburn treatment and foot massage for US$50.
Secret Garden masseuse Lee Nyhus also works at Robert’s Grove Beach Resort Spa (tel. 501/523-3565), north of town, where you can get a full range of treatments—for more premium prices, of course. The Turtle Inn also has pampering services, as does a Thai massage place right in Placencia Village Square, run by experienced Thais who offer seaweed treatments and papaya body polish (massage US$75 per hour). Also check into Z-Touch Beauty Salon and Massage (tel. 501/523-3513, massage US$50 per hour).