Phuket's Magnificent Underwater World

With as little as 24 hours up your sleeve, you can enjoy three different sites – a rock, a wreck, and a reef – and still be back for happy hour. Several boats leave daily from Chalong Bay and take in three dive sites all within an hour’s cruising.

The most famous is probably Koh Dok Mai or Flower Rock, which is also the most characteristic of the region, being a limestone pinnacle that rises steeply from the ocean floor. Underwater it presents as a wall with vertical gutters and crevices and even some caves, home to all sorts of cryptic crevice dwellers.

The next dive, the wreck, is on a sunken car transporter ferry, which is so big you won’t get to see all of it on the one dive. And the coral, called Anemone Reef, for good reason guarantees you some of the cutest Clownfish around. Over the course of the day you could see anything from seahorses to scorpionfish, barracuda to banded coral shrimp.

These day boats have all the dive gear you need on board. As well as showers, they provide towels and serve you breakfast and lunch. So all you really need for the day is your dive card, sunscreen and swimming gear.

Prefer to hit the sands? Try these: The Best Beaches in Phuket

Find out why Thailand is so special: Why Thailand is a Traveller's Paradise... and How we can Keep it That Way

If you have two or three days to spare, it is worth heading over to Koh Phi Phi. One reason is it’s even more relaxing than Phuket, but another is for the great diving on Phi Phi Ley or Little Phi Phi, a short boat ride to the south of Koh Phi Phi.

The terrain here is also limestone pinnacles made famous by the James Bond movie The Man with the Golden Gun, and more recently by The Beach, starring Leonardo DiCaprio. The range of diving is immense, from easy snorkelling in Lana Bay on the north-western tip of Koh Phi Phi, to Bida Nok, which offers a dramatic marine topography: caves, swim throughs, drop-offs and overhangs.

All around Phi Phi Ley are steep walls and coral banks with an amazing number and diversity of nudibranchs, as well as the usual colourful reef fish like butterfly fish, coralfish and parrotfish. On Koh Phi Phi you’ll find a range of resorts to suit all tastes and budgets, and there are plenty of dive operators to choose from.

If you have four days or more available, you’d be crazy not to book a liveaboard trip and head out to the Similan and Surin National Parks – about six hours’ cruising from Phuket (which is usually done while you sleep). Here you will be spoilt with some of the best diving in the region.

The islands here are massive granite boulders, stacked up long ago by some giant god of the sea, to create a playground for fish and divers alike. Diving in this area you may be lucky enough to see manta rays cruising through, but you’ll certainly find turtles, and some of the biggest giant morays I have ever seen. Mix in powder-blue surgeons, white collar butterflies and black tail angels and you’re in for a visual feast.

The pinnacle, literally, of the trip will be Richelieu Rock, a boulder so famous it even has its own website. A large, horseshoe-shaped rock, completely submerged, Richelieu is home to everything from the smallest ghost pipefish to hordes of batfish, schools of swirling snapper, and giant cuttlefish. Even three dives on the rock won’t be enough: you’ll be planning your next trip on the way home.

Follow Deborah on Twitter @where2nextblog or visit her blog, Where to Next?, all about travelling with teens and mid-life style. Find out more on Thailand diving at Diveplanit.