It’s a traveller’s dilemma. What do you do if you want to watch the sunset from a totally unspoilt tropical beach, but you quite fancy doing so while lying on a teak lounger with a world-class cocktail in your hand? And if you enjoy being lulled to sleep by the uninterrupted chorus of nocturnal insects, but you don’t want your bed to play host to the wriggly performers?

The Thai island of Ko Chang, 200 miles southeast of Bangkok, might just have some of the answers. It combines the luxury of Singapore Slings and air conditioning with that self-satisfaction of being somewhere that not many people know about yet — a bit like Notting Hill before Hugh Grant.

It’s Thailand’s second-biggest island, after Phuket, but — for the moment, at least — it receives a tiny fraction of the tourists. You can swim without the danger of getting mulched by a wetbike or deafened by a passing disco “pirate ship”.

We were staying at the Tropicana Resort & Spa, a group of bungalows that were luxurious inside but tropically rustic outside. Thick stands of native plants covered practically every inch of the grounds except the swimming pool. Many of the paths within the resort were walkways over streams teeming with fish, some of which looked suspiciously like piranha. A good way of cutting down on drunken guests, I imagined. But no, a waiter assured me, they were only carp.

That sounds like a quick conversation, but it took about half an hour, because the thing about being in a place that isn’t used to mass tourism is that the locals haven’t yet had a chance to adjust to the nonsense that visitors are likely to say to them. So the initial inquiry from an Englishman as to whether these carp were in fact a species of South American fish that the poor waiter had never heard of did not exactly hit home instantly. Then there was the whole stage of “Look, ha-ha, I’m joking about being scared that they’re going to eat me”, which was met by the young Thai with polite bewilderment and an obvious desire to be somewhere else. By the time we got on to the same basic wavelength and he explained that guests could buy bags of food with which to feed the fish, which was why gangs of them followed your progress along the walkways, we were both almost dead of sunstroke.

The hotel’s in-room information file was just as comprehension-challenged. Its medical advice section suggested that if one burnt oneself, “strong acid and alkalis can relieve the pain”. Presumably by replacing it with agony.

In the resort’s beachside restaurant, there was little danger of confusion, because the hotel has been open for a few years now, and the staff have heard the menu pronounced by every type of Western — and Asian — tongue. But the Tropicana is still at that stage in its development when dinner has to be accompanied by “sophisticated” music, which means either traditional Thai percussion — a bit like being trapped in a lift with a drunk xylophone player — or a Filipino with his Yamaha set to “hotel schmaltz”. At least the cheap restaurants usually have only a tinny radio, which I found much easier to ignore.

At the southern end of our beach, there were a couple of restaurants on stilts — large thatched platforms poking out over the water, from which you could sit and look down at the fish and crabs that hadn’t yet been netted and added to the menu.

Ko Chang, like the rest of Thailand, is very hot on hygiene, so there was no problem eating fresh seafood and drinking iced drinks even at such a primitive-looking place. But ordering could sometimes be difficult, because the gang of teenagers who ran the restaurant spoke only rudimentary English. This, of course, was nothing to be ashamed of: after 10 days, my Thai was limited to “hello”, “thank you” and “Chang” (a cheap brand of beer); and most of the diners were Thai, so English wasn’t essential for business.

The bilingual menu promised such baffling dishes as “scratched egg” and “smoked salmon serve with pickle crapper”. I eventually discovered that their basic fried rice with seafood, with an optional spicy sauce that I could dose myself, was a meal I never got tired of, and came in at about 75p.

Strolling back the half-mile along the palm-fringed shoreline was a trip through the stages of a tropical island’s development. First, there was a place that is very popular with Thai visitors, the Magic Resort, an eclectic group of bungalows ranging from Margate beach huts to mini Swiss chalets, with (gasp) no pool and (even gasper) no “and Spa” in its name. Everything in the world of travel seems to be called something “and Spa” these days.

Just along from Magic was the swankiest place on the beach, but it had as much Thai charm (from the outside at least) as Brighton Marina.The biggest surprise came 100 yards further on — a stand of coconut palms harbouring a row of little cabins. And judging by the lack of bodyguards, it was not Brad and Angelina’s paparazzi-proof hideaway. Yes, unbelievably, there were still locals living on the beach.

Next down was a simple bamboo shelter with four mattresses — a little open-air massage hut, just like similar ones all along the beach. After all, the whole country ought to be called Thailand and Spa. But the ladies working here made no concessions to the wimpish western concept of the “relaxing massage”.

Lying on my sacrificial altar, I wondered if it was entirely necessary for the masseuse to dislocate my toes, insert her fingers into my skull via my tear ducts, jam a foot into my groin and, even more incredibly, get me to jam my own foot into my groin, something I haven’t been able to do since I was about 12. At one point, she started punching me in the kidneys with a boiling-hot lemon-oil sponge.

Then something magical happened. As she tried to perform an appendectomy with her bare fingers, then stood on the backs of my legs as if they were waterskis, I began to enjoy it. I was lying beneath a thin palm roof that itself was being pummelled by a tropical rainstorm, with the thunder growling and grumbling back and forth across the bay. A light spray was falling on my shoulders, taking the edge off the steamy heat. I could finally feel my body loosening up. Before starting, it had been as supple as a sheet of uncooked lasagne. Now it was al dente, and smothered in hot lemon sauce.

It was the massage that gave me the strength to get over my resort fever. It is, after all, easy to slip into a mindset where the biggest decision of the day is what to drink at happy hour. But after the massage, I remembered that there was a world beyond the beach.

Ko Chang is a mountainous island, rising to 2,400ft. It is covered in dense jungle interspersed with rubber and fruit plantations, and is protected as a national park. I decided to play Doctor Livingstone, and took an elephant ride, or rather elephant rollercoaster, into the jungle.

Asian elephants are hairy, round-shouldered creatures whose one aim in life seems to be to graze on the soft grass growing under trees. If that means jamming their passengers between branches crawling with the kind of ants that leap onto bare flesh, stand on their front legs and start lunching, the elephants don’t care. And sometimes the elephant-driver takes a long time to find reverse. It was fun, though, bouncing past huts where fresh strips of latex had been hung out to dry and eating hunks of sweet local grapefruit picked while the ants weren’t looking. And, although some people got queasy, the rolling motion was no problem for me because I live in France, and an elephant ride is by no means as rough as the suspension on a 2CV.

In the southwest corner of the island, a half-hour drive in an open-backed taxi, lies what is described as the “picturesque fishing village on stilts” of Bang Bao. The stilts are still there, but nowadays it is as much a picturesque fishing village as Grimsby. This is where development on the island has been concentrated: every other building is a souvenir shop or diving centre. Practically everyone who comes to Ko Chang heads at some point to Bang Bao for a diving or snorkelling trip.

For the first time during the holiday, I felt like a herd animal. Our ex-fishing boat was slowly being loaded up with the day’s catch of Thais, Germans, French and Americans. The Thai captain turned on his radio and began humming to Bob Marley, and I wished I was back on my deserted beach.

But I would have been wrong to jump ship, because the day’s snorkelling turned out to be the best part of the holiday. We headed due south, chugging for an hour past deserted green islands, and eventually moored off a tiny atoll. The water was so crowded with fish that I thought I’d landed in a roll of Nemo wallpaper. The multicoloured coral and swaying anemones were stocked with all the stars of the film except the sharks, from tiny angelfish to fat, goofy parrotfish, which were unecologically pecking at the reef.

During our day at sea, we stopped at three equally well-preserved atolls, and each time members of the crew took us on guided swims. And this is where the whole development question really hits home. The reef, like the rest of Ko Chang, is well preserved for the moment. But it is, as they say, “under pressure” — because we weren’t the only boat out there. At each atoll, there were at least two boats of equal size. Until I swam away from the throng, I occasionally felt as if I was taking part in a snorkellers’ riot. Harmless fun or the beginning of the end for the reef? A bit of both, I think.

Back at the resort, after a painful après-soleil creaming of all the crannies we hadn’t covered in factor 50, we went down to the beach to enjoy the moment when the sun disappears and, as if turned on by remote control, the frogs and insects start singing.

After a day sucking salt water through a snorkel, my cool sundown cocktail tasted especially good. I’d opted for a pure watermelon juice, a pinky-red mush that saves you the trouble of spitting out the pips.

“What a beautiful colour,” I said to the waiter. “It’s like drinking the pink clouds on the horizon.”

He smiled nervously, clearly trying to work out whether an Englishman really was stupid enough to ask him if melons grew in the sky.