Kate Roff submerges off the coast of Thailand to meet a local celebrity.

Off the tropical coast of Koh Lanta, Thailand, lives a fish named Porkie. It may sound like the beginning of a children's story, but it's true. "Porkie" is the name local divers have given a particular porcupine fish, adopted as a kind of wild pet by the dive companies operating in the beautiful marine park.

"Everyone knows him," explained Kim McMenemy, who runs dive operation Scuba Fish. "He's kind of a local celebrity. He's a bit like a pet dog, he follows you around until you stop and give him some attention."

Porkie is part of the puffer fish family and is easily recognised thanks to a small scar on his mouth, which divers believe must be from a lucky escape in a fishing incident.

So well-known, is Porkie, that he even has his own facebook page. "He has more facebook fans than both our dive shops put together," Kim admitted.

While Porkie may be a favourite, the dive sites in the region have plenty of other species to showcase. We accompanied Kim for a dive at Koh Haa, a cluster of six uninhabited islands off Koh Lanta, which boasts some of the world's best underwater scenery.

There was so much to see just below the calm surface that Kim was able to pick and choose what she pointed out to divers. She indicated a colourful banded sea snake to some divers while tactfully redirecting other, snake-shy tourists' attention to some brilliant blue coral.

Kim has been diving here for almost 11 years and expertly identified the stunning groups of damsel fish, angel fish, snapper, travelly, barracuda and clams that surrounded us as we meandered along in the warm (29C) water. She even knew where to find some tiny, juvenile black-tip reef sharks, which, regardless of sharks' reputation, really were magnificent to watch.

Scuba Fish runs several dive programmes, all Padi-approved, including a one- to two-day "Discover Diving" course, which allows inexperienced divers to dive down to 12m with an instructor. This particular course has proved popular with travellers looking to avoid spending precious holiday time on a full diving course, but with the advantage of still getting underwater.

"A lot of others are getting onto Padi's e-learning system too," Kim said, "They do the theory online before they arrive in Thailand, and then get the do the practical diving side of things while they're here."

Unlike many diving operations, Scuba Fish focuses on keeping groups small, with constant attention supplied by enthusiastic staff. Liquid Lense, the company's photography and videography course, also enables divers to try their hand at capturing some of what the see underwater.

Victoria MacKenzie runs the course, and believes the region offers some of the most diverse marine life in some of the clearest waters - ideal for trigger-happy photographers.

"We've recently been really lucky and had these huge manta rays here for over a month," she gushed when asked about her preferred subject under water.

"But," she confesses, "Porkie remains a favourite - he really does know how to pose for a photo."

Getting there: Qantas Airways has regular flights from Auckland to Phuket via Brisbane.

After flying into Phuket, a public ferry or private speedboat can zip you off to Koh Phi Phi or Koh Lanta. Book them at the dock, or get your hotel to include a transfer.

Where to stay: While Porkie may have the best accommodation under the water, above sea level try Koh Phi Phi at Zeavola. This luxury resort is high-end living in isolated natural surroundings. Check out their specials at zeavola.com.

What to do: Scuba Fish can be found at scubafish.com.

Porkie's facebook page is at facebook.com/porkie.lagoon.

Further information: See The Tourism Authority of Thailand's website.

Kate Roff flew with the assistance of Qantas.