Dive Right In

You'll find some of the best dive sites in Africa in Zanzibar's waters, with experienced divers citing the incredible array of species as one of the main draws. Visibility, ranging from 15m to 60m (49 ft.-197 ft.), is also usually good, and water temperatures range from 25°C to 29°C (77°F-84°F). The diving season is from September to March, but that's not to say it's not worth diving at other times. The best diving is at Mnemba Atoll off the northeast coast, referred to as "the tropical fish capital" of Zanzibar. Surprisingly, the reefs near Stone Town are also very satisfying to dive, particularly Murogo Reef and, to a lesser extent, Boribu Sandbar. Pange Island is another good site, located 1.5km (.9 miles) southwest of Stone Town, as is Bawe Island, a 30-minute boat ride from Stone Town, where there is a reasonably good snorkeling reef. Aside from fish, these sites offer a great selection of coral; Stone Town also offers wrecks to explore. If you are based on the southeast coast, Jambiani Reef and Stingray Alley (also near Jambiani) are good sites to dive. Essentially, the south offers slightly deeper dives than the north and is better if you're keen to see bigger marine life. But the north is where you see the greatest variety, and aside from Mnemba Atoll, Levan Bank near Nungwi is a must.

One of the oldest and most reputable dive outfits, One Ocean Zanzibar Dive Center (tel. 024/22-8374; www.zanzibaroneocean.com), is also the biggest dive operator in East Africa, with a reputation for excellent dive instructors, tip-top equipment, and a serious attitude to safety. There is a One Ocean Dive Centre in Stone town; there are also a number of One Ocean Dive Centres operating from many of the lodges reviewed under "Where to Stay." Other good dive centers are Rising Sun (www.risingsun-zanzibar.com), servicing Breezes, Baraza, and The Palms; and Reef Leisure Watersports (www.reefleisure.com), operating at Fairmont, Kempinski, Pongwe, and Matemwe Bungalows.

Snorkeling with Dolphins

Situated on the southern point of the island (about an hour from Stone Town), the laid-back fishing village of Kizimkazi is the site of a 12th-century Shiraz mosque, thought to be the earliest evidence of Islam in East Africa, but it is more famous for the schools of bottle-nose dolphins that swim within a few minutes' boat ride from its shores. If you are lucky, you may be able to jump in and swim quite close to the dolphins, in which case the experience gets three stars. However, while there is an 85% chance of spotting dolphins, it is not always possible to swim with them. Be aware that some of the locals, almost all of whom earn more from dolphin trips than fishing, can be unscrupulous. It is very distressing for the dolphins to be chased or interfered with, particularly during breeding season, so do not insist that your skipper to get closer, and please dissuade others on the boats from doing similar. It is not unknown for tourists to offer to pay the skipper more regardless of the dolphins' moods or needs; should you encounter this, I urge you to make your discomfort very clear. Also, do not make a huge commotion by jumping overboard (try to slip in surreptitiously, and not all at the same time). Note that while your chances of seeing the dolphins is not guaranteed, it is highest the earlier you get there; 7am or even earlier is considered ideal, but this makes for an uncomfortably early start if you're coming from Stone Town. If you're really keen for a dolphin encounter, I recommend you book at nearby Unguja Lodge. This means you can get there early and try more than once, and the guys at the dive center are also extremely sensitive to the dolphins' needs. If you visit Kizimkazi, pop into the mosque and look for the remains of an 18th-century stone wall (just above the high-water mark on the beach) that once formed a defensive perimeter around the whole settlement. According to legend, Kizimkazi is named after the merchant who built the wall; when he was captured by the Portuguese, the original Kizimkazi begged for a final prayer session on the beach, whereupon he promptly hopped over his own wall and escaped.

Snorkel Safety -- You can drift for hours mesmerized by the life below, cooled by the ocean currents, and only realize that evening, when the searing pain sets in, how fiercely that sun beats down. Wear a T-shirt or rash vest to protect your back from the sun, and don't forget to slather the backs of your legs liberally with waterproof sunblock. Be careful also of grazing yourself on coral. While it looks like pretty benign underwater flora, corals are actually animal colonies with calcified outer skeletons that have sharp edges; accidental contact can leave a small amount of animal protein and calcareous material in the wound. What appears initially to be a small and harmless graze can develop into a suppurating infected wound that requires specialist intervention. To avoid this, scrub and flush the cut or graze with fresh water, then rinse with vinegar, isopropyl alcohol, or a mixture (50:50) of hydrogen peroxide and water; rinse daily with this mixture. Having suffered from a prolonged infection, I would also apply a topical antibiotic ointment three to four times daily. If the infection persists or spreads, an oral course of antibiotics may be needed; I suggest you make an appointment with your doctor immediately. The best snorkeling sites are Mnemba Atoll in the northeast and Chumbe Island near Stone Town.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.