Snorkel or dive

Snorkeling or diving means putting your face underwater where fish, coral and turtles live. Snorkeling takes a mask, fins and ten minutes of practice; scuba diving takes a short course with an instructor. Either way, the first look under the surface of a healthy reef is the moment many travelers come back for.

Where to do it

Great Barrier Reef, Australia

Day boats from Cairns and Port Douglas run to the outer reef, a World Heritage Site, many to moored pontoons where beginners can snorkel from a platform or try a first dive. From November to May, tropical Australia's waters carry dangerous jellyfish, so wear the full-body stinger suit the boats provide.

Red Sea at Sharm el-Sheikh, Egypt

Warm, clear water with coral close to shore, and Ras Mohammed National Park a short boat ride away. Dive centers in Egypt here run courses for every level. Some sites have strong currents, so pick a guided trip that matches your experience, and check your government's travel advice for Sinai.

The Maldives

Many resorts sit on an island ringed by a house reef, so you can snorkel straight from the beach with reef sharks, rays and turtles. Manta rays gather at some sites in season. Resorts in the Maldives are a splurge; guesthouses on local islands cost far less.

Raja Ampat, Indonesia

Hundreds of islands off West Papua, at the heart of the Coral Triangle, with reefs packed with life just below the surface. It's remote: you fly via Sorong, then take a ferry, and pay a marine park fee. This corner of Indonesia suits divers and snorkelers with time.

Cozumel, Mexico

An island off the Yucatán known for drift dives along walls, where the current carries you past the reef. Inland, the cenotes are freshwater sinkholes you can snorkel in daylight; going into the caves needs special cave training. Dive shops on this island in Mexico offer beginner courses.

Bonaire, Caribbean Netherlands

The whole coast is a protected marine park, and yellow-painted stones by the road mark where to walk in and dive straight from shore. Divers pay a nature fee and attend an orientation. Bonaire is ideal for diving at your own pace.

Belize Barrier Reef, Belize

A UNESCO-listed reef running the length of Belize, with easy snorkeling at Hol Chan Marine Reserve off Ambergris Caye, where nurse sharks and rays gather. The famous Great Blue Hole is a deep dive for experienced divers only.

Silfra, Iceland

In Thingvellir National Park, you snorkel or dive in a crack between two tectonic plates, in glacier water so clear you can see far ahead. It's about 2 to 4 °C all year, so operators supply drysuits and require a guide. Expect cold hands and a dive like no other in Iceland.

How to make it happen

• Learn with a certified instructor. An entry-level open-water course usually takes three or four days; a try-dive with an instructor lets you test it in one morning without a certificate.
• Be honest on the medical form. Divers fill in a health questionnaire, and some conditions, such as asthma or heart problems, need a doctor's sign-off.
• Never hold your breath on scuba. Breathe slowly and steadily; your instructor will cover why.
• Wait before you fly. Divers Alert Network advises at least 12 hours after a single no-decompression dive and 18 hours after several dives or several days of diving. Plan the dive days early in the trip.
• Snorkel with a vest if you're not a strong swimmer, stay with a buddy, and go on guided trips where currents run.
• Don't touch the coral or stand on it, and cover up with a rash vest instead of lots of sunscreen.

Seeing turtles or sharks here also counts for wild animals in the wild.