Diving, the Azores

For world-class diving sites you can reach on a budget airline, try the Azores archipelago. The seamounts (volcanic underwater elevations) have barred hogfish and stingrays on the seabed, and devil rays and skipjack tuna closer to the surface, plus dolphins, turtles and whales to spot on the boat there and back. Divers can swim with 10-metre whale sharks off the coast of Santa Maria island, and with blue sharks around the Condor seamount, 10 miles from Faial island. The Rosais reef, off the western tip of São Jorge, is a more accessible place to find a wide variety of sealife, including octopus and huge schools of pelagic fish, and there is the Dusky Grouper Passageway off Corvo, where divers are often followed by the eponymous big, friendly fish. Caves and shipwrecks complete the package.

• More information at dive.visitazores.com. Ryanair flies from Stansted to Ponta Delgada from about £45 return. Dive Worldwide offers group and tailor-made eight-day trips from May to October from £1,045 including flights

Underwater photography, Malta

Blue Hole – considered one of the world’s best dive sites. Photograph: Getty Images/iStockphoto

Photographer Pete Bullen runs underwater photography trips around Gozo, Malta and Comino from May to September (he switches to landscape photography over the winter). Gozo has some of the best diving in the Mediterranean; Jacques Costeau classed the Blue Hole as one of the top 10 dive sites in the world. Other photogenic spots include the recently fallen Azure Window, the Inland Sea, the Double Arch and the shipwrecks at Xatt L’Ahmar. As well as the impressive underwater topography, photographers can capture large shoals of damselfish, amberjacks and flying gurnards. Suitable for experienced divers only (minimum Padi advanced open water or BSAC sports diver), but any level of photographer welcome.

• Sample packages excluding flights: three days’ guiding and coaching and four nights’ B&B for €230pp, or €370 for five days/six nights, oceanfoto.co.uk

Freedive yachting, Croatia

The many islands, caves and wrecks of Croatia offer exhilarating diving. Photograph: Samo Jeranko

Samo Jeranko, a world vice-champion freediver, leads sailing and freediving holidays in Croatia. There are two routes: one trip explores some of the 140 islands of the Kornati national park, where the cliffs fall to lung-busting depths of 100 metres. The other is a diving and spearfishing adventure around the islands of Vis, Hvar and Solta, where there are wrecks and underwater caves. Both trips include paddleboarding and yoga sessions. The fleet comprises three six-cabin sailboats and a catamaran, plus a speedboat to reach the most breathtaking diving destinations.

• €1,190 for a week, excluding flights, available for fixed dates once a month from May-September 2018, freedive-yachting.com

Underwater museum, Lanzarote

Sculptures by Jason De Caires Taylor off Lanzarote.

The Museo Atlántico is the only underwater sculpture park in Europe, showcasing artworks by Jason deCaires Taylor (he has other subaqua sculptures in Grenada and Mexico, and is planning a new park in Australia). The site is in a sheltered area near Playa Blanca, at a depth of 12 to 15 metres. The 10 groups of sculptures include children in boats, half-human, half-cactus hybrids, and a 200-person strong human gyre. They are designed as an artificial reef that create a habitat for marine life, such as angel sharks, giant tuna, barracuda, mola mola, and many kinds of rays.

• Museum entry €12, two-hour snorkelling tour €34, diving from €39, Dive College Lanzarote has different packages for snorkellers, dive novices and qualified divers

Swimming, Mexico

Swimming off Baja California

Swimtrek’s latest open-water holiday destinations include the Isles of Scilly, Ibiza and the Galapagos Islands, where swimmers share the water with marine iguanas, fur seals and turtles. On this tried and tested trip to the Baja California peninsula the Sea of Cortez is a balmy 27C and swimming buddies are sea lions. Swimmers circumnavigate remote islands to reach deserted beaches, passing pearl beds and frigate bird colonies. Accommodation is cabin-style tents on the beach on Isla del Espiritu Santo, so guests can make good use of the snorkels, kayaks and standup paddleboards.

• 2018 dates to be confirmed; in 2017 the one-week trip started at £1,370, excluding flights, swimtrek.com

Yoga scuba, Philippines

One of the beach sites for yoga sessions, complete with swing. Photograph: Arno Enzerink

Reconnect Discover runs yoga and diving retreats on Camiguin island in the Philippines. The six-day retreats typically include (for qualified divers) six dives and four yoga sessions or (for beginner divers) a Padi open-water course and five yoga sessions. Breakfast, lunch, a massage and one or two island excursions are included. Camiguin has about 20 dive sites, including the Old Volcano, home to frogfish, rays, seahorses and whitetip sharks.

• 2018 prices to be confirmed, a five-day retreat in 2017 started at £411 (qualified divers) and £566 (for a Padi course), excluding flights, reconnectdiscover.com

Reef conservation, Belize

Lionfish monitoring in Belize

Responsible Travel offers about 30 marine conservation holidays, from dolphin research in Greece to protecting turtles in Costa Rica. On this reef conservation trip in the Sapodilla Cayes marine park in southern Belize, volunteers do two to four dives a day to carry out reef and coral checks, conduct queen conch and lobster surveys, and to monitor the invasive lionfish population. Divers may see hawksbill and loggerhead turtles, spotted eagle rays, manta rays, dolphins and whale sharks. Night dives among bioluminescence are a highlight of the trip.

• From £895 a week excluding flights, responsibletravel.com

Sea kayaking, Indonesia

Kayaking in Komodo national park

The most famous inhabitant of the Komodo national park is the land-dwelling dragon but the sea is teeming with life too. No Roads Expeditions runs sea kayak trips around these Lesser Sunda islands, and snorkelling is a key part of each day’s itinerary – with rays at Manta Point, around the reef at Sebayor Kecil. Divers can add on a couple of dives to see more coral, turtles and perhaps the endangered manatee-related dugong. There are excursions to grottoes and fishing villages; a night on a mangrove island inhabited by thousands of bats; and, of course, a ranger-led trek in search of the eponymous dragons. Guests sleep in safari-style tents on a different island every night.

• Five-day trip AU$1,500 (around £890), 10 days about £1,540, excluding flights, March to December, noroads.com.au

SUP safari, Palau

Rock Islands, Palau. Photograph: Alamy

The island nation of Palau in the western Pacific is classed as one of the seven underwater wonders of the world by Cedam International, an inter-governmental marine environment organisation, and is nicknamed the underwater Serengeti because of its rich sealife. One way to explore the islands is by standup paddleboard: many of the Rock Islands are seldom visited, and the clear water means SUPers can look down at the reefs, shipwrecks and even sleeping sharks. Palau Dive Adventures rents out SUPs and can arrange day tours. The same company has a budget dive package with 13 dives over five days – including one at Blue Corner, where there are up to 13 species of shark – and seven nights of basic accommodation.

• A week’s dive package from US $1,430 excluding flights, palaudiveadventures.com

Snorkel trails, Scotland

A black brittlestar, bryozoans and orange sponge off the west Scottish coast. Photograph: Ben James/Scottish Natural Heritage

Scottish seas might be chilly but they are full of fascinating creatures, from sea squirts, sponges and anemones to whales, dolphins and basking sharks. The Scottish Wildlife Trust has established two snorkel trails in areas with lots of underwater life: the north-west Highlands around Ullapool, and the Isle of Harris. The former has nine snorkel spots, including sheltered bays for beginners and offshore reefs with fish-filled kelp forests for advanced snorkellers. There are six snorkel sites in North Harris, including a sea loch, a sandy seabed with sunstars and the reefs off spectacular Hushinish beach, where shoals of sand eels swim.

• Download the snorkel trail leaflets