You don't necessarily have to strap on gas tanks to see spectacular sights beneath the waves. In some places, all you need are a mask, flippers and a snorkel. This lack of cumbersome equipment can be liberating. It encourages a long, languorous approach to underwater exploration, stretching it out over a day rather than compressing it into an hour or so. These places, some of the finest places to snorkel in the world, also happen to have beautiful coastlines as well.
1 The Maldives
This string of nearly 1,200 coral islands in the Indian Ocean copes with an annual influx of tourists greater than its total population, while rising sea levels threaten to engulf the country, whose average ground height is 1.5m above sea level.
Add to that the devastation caused by the tsunami in 2004, and the tragedy of this place becomes almost Shakespearean in quality: beauty and ruin are inextricably intertwined. Yet it is one of the most spectacular places to snorkel in the world. Lily Beach Resort, on the tiny Ari Atoll, has coral reefs metros from the shore where you can see all manner of vibrant reef dwellers, from fish to turtles. Refurbished in 2009, the resort's deluxe water villas have marble and wood interiors and sit on stilts above the water - the perfect base for leisurely snorkelling expeditions.
Water villas at the Lily Beach Resort and Spa (www.lilybeachmaldives.com; 00 960 668 0013) cost from US$1,593 (Dh5,851) per night, based on two sharing, including meals and drinks.
2 Hol Chan Marine Reserve, Belize
The Mesoamerican Barrier Reef System, the second largest reef in the world after the Great Barrier Reef, extends through Belize, Guatemala, the Honduras and Mexico. Belize is good for English speakers because its official language is a Creole dialect of English. The Hol Chan Marine Reserve, a few kilometres from the town of San Pedro and about 15 minutes by boat, is perfect for a day trip snorkelling on the reef. The reserve is divided into different zones according to its different habitats. The reef channel is home to a wide variety of fish including jacks, snappers and barracuda, as well as turtles and dolphins. Manatees - also known as sea cows - swim in the seagrass beds.
Discovery Expeditions Belize (www.discoverybelize.com; 00 501 671 0748) has a three-hour tour from US$35 (Dh129) per person, including equipment and drinking water. There is a park fee of $10 (Dh37) per person.
The Republic of Palau, an island nation in the Pacific Ocean about 800km east of the Philippines, is one of the world's outstanding diving and snorkelling destinations. It consists of more than 200 volcanic and coral islands that host hundreds of species of coral and thousands of species of fish. One of the best ways to explore this realm is by sea kayak. This 11-day trip takes in Rock Island, a beautiful cluster of mushroom-shaped limestone rocks whose tops are covered in jungle and whose bottoms have been eroded by the sea. Turtles and huge schools of fish congregate around the so-called "Big Drop-Off", where the sea bed plummets hundreds of metres. Nearby is Jellyfish Lake, where you can safely swim through thousands of jellyfish that have evolved without a sting.
An 11-day sea kayaking tour with Wilderness Travel (www.wildernesstravel.com; 00 1 510 558 2488) costs from $4,995 (Dh18,347) per person, including accommodation, meals and kayaking equipment; snorkelling equipment not included.
4 Ningaloo, Australia
Smaller, more remote and much less busy, Ningaloo Reef on the west coast of Australia is often eclipsed by the Great Barrier Reef on the east coast. Lying more than 1,200km north of Perth - one of the most remote cities in the world - this 260km-long coral reef is nevertheless worth the long trek.
Ningaloo also is Australia's largest fringing reef, which means a cornucopia of fish, manta rays, turtles and sea snakes is not more than a few metres from the shore. The other big draw is the whale sharks. Up to 12m long, they are the world's biggest fish, coming here for the plankton-rich waters between April and July each year. They often glide close to the surface and eat mostly algae and krill, meaning it is possible to snorkel close to these giant fish without peril.
A whale shark tour organised by Ningaloo Reef Dive (www.ningalooreefdive.com; 00 618 9942 5824) costs A$376 (Dh1,451) per person, including snorkelling equipment and lunch.
5 Koh Tao, Thailand
Koh Samui has luxury resorts and Koh Pha-Ngan has parties, but Koh Tao, the smallest of the three famous islands in the Gulf of Thailand, is where people come to learn to dive. Diving shops pepper parts of this island that is just more than 20 sq km, and there's a steady stream of people trying for a PADI diving certificate. The qualities that make it good for learning to dive also make it great for snorkelling: shallow coral reefs, big boulders and rocks, and stretches of white sand. Angelfish, butterfly fish, stingrays, turtles and blacktop reef sharks live in this varied environment. Haad Tien Beach Resort, south of the island, has a house reef that lies only a few metres from the resort's private beach. The resort can also arrange day trips on one of its boats.
Double rooms at Haad Tien Beach Resort (www.haadtien.com; 00 66 7745 6580) cost from 3,320 Thai baht (Dh384) per night, including breakfast and taxes.
6 Fernando de Noronha, Brazil
Only a few hundred visitors are allowed at any time on this archipelago about 350km off the coast of Brazil. This beautiful place was declared a Unesco World Heritage Site in 2001 and is considered one of the best dive and snorkelling sites in South America.
Baia do Sancho, a remote spot reachable by boat or a series of ramshackle ladders, is a lovely bay girded by high cliffs. Hundreds of different types of fish as well as turtles and dolphins gather in the clear blue waters. The best time for snorkelling on this inner coast is between August and December. Mar de Fora, the island's southern coast, is open to the Atlantic and has good snorkelling in January and February.
Blue Parallel (www.blueparallel.com; 00 44 20 8819 3904) has seven-day tours to Fernando de Noronha from around 15,340 Brazilian real (Dh31,221) per person.
7 Ras Muhammad National Park, Egypt
About 25km down the coast from Sharm el-Sheikh, Ras Muhammad National Park was established in 1983 and covers about 480 sq km. Sitting at the confluence of the Gulf of Suez and the Gulf of Aqaba, the reserve teems with a diverse range of marine life. There are more than 220 species of coral. Fringing reefs, which are close to the shore and often less than a metre below the surface, are ideal for snorkelling. The park is home to thousands of different underwater species including puffer fish, star fish, eagle rays and sea turtles. It is a great place to snorkel throughout the year, but the water is warmer between June and September and cooler in January and February.
Aqua Nabq Dive Center (www.aqua-nabqdivers.com; 00 20 103 317 485) organises day trips to Ras Mohammed from 200 Egyptian pounds (Dh121) per person.
8 Niihau, Hawaii
Elizabeth Sinclair bought Niihau in 1864; today, fewer than 200 residents live on the island, sustained by solar power, rainwater catchment and regular barge deliveries. Hawaii's smallest inhabited island is also called the "forbidden island", because access was restricted until the late 1980s, when boat and helicopter tours to the island began.
This cloistered realm, home to endangered Hawaiian plants and flowers, was used as the backdrop to the film Jurassic Park (1993). The coral reefs are home to hundreds of different types of fish, including parrot fish and angel fish. Manta rays, spinner dolphins and Hawaiian monk seals are also regularly seen in the area. Pupu, tiny shells classified as gems, can be found on the island's beaches, fetching thousands of dollars as ornaments and jewellery.
Holo Holo Charters (www.holoholokauaiboattours.com; 00 808 335 0815) has a day tour to Niihau from US$159 (Dh584) per person, including breakfast, lunch, drinks and equipment.
9 Bunaken National Marine Park, Indonesia
This marine park at the north-eastern tip of the island of Sulawesi is famous for its crystal clear water and diversity of marine life. Visibility is often between 20m and 35m. The 80,000-hectare park, established in 1991, has more types of fish than the Great Barrier Reef. Indeed, 70 per cent of all fish species in the Western Indo-Pacific are found in this area. The park has nearly 60 different types of coral, as well as turtles, dolphins and dugongs. Yet rubbish and other detritus from conurbations such as Manado threaten to spoil this unique marine reserve. Dive operators, local associations and the Indonesian navy have been involved in clean-up projects. Head to Murex, one of the first resorts to open in the area and a great base from which to plan snorkelling trips; it offers boat trips to the park.
Murex (www.murexdive.com; 00 62 431 838774) has double rooms from 481,570 Indonesian rupiah (Dh193) per person, based on two sharing, including meals and taxes.
10 Bay of Naples, Italy
Exploring Roman ruins tends to be a hot and dusty affair, so the Archaeology Park of Baiae makes a refreshing change. These ruins, which cover an area three times the size of Pompeii, have been a few metres below the bay of Naples since the first century AD. An Italian professor discovered them in 1959 and they became a protected marine area in 2002. The park has a lot to explore. A nymphaeum - a shrine to mythological spirits with a handful of beautiful statues - sits in a few metres of water. A bit deeper down is a Roman villa with splendid mosaics, and a building complex that used to house thermal baths. Many of the artefacts are in surprisingly good condition, despite being under the waves for thousands of years. The water is warmest from June to September, but visibility can be poor.
Napoli Diving Centre (www.napolidivingcenter.it; 00 39 081 853 1563) organises day trips from€20 (Dh96) per person, including equipment.