XTREME FUN: Fear and foaming in Nan

The first raft darts into the rapids and is quickly heaved into the whirlpool.

Our plan calls for a leisurely 80-kilometre paddle in five inflatable rafts, with a few wet thrills thrown in, from the village of Sob Mang on the middle section of the Wa River to Mae Jarim.

It will weave us through wild water, sheer canyons and evergreen forest - leisurely but not simple: along the way are rapids with cringeworthy names like "Wild Ghost" and "Dancing Tiger".

"If the forest isn't fooling me," says Tin, the captain of our raft, "we've gone five kilometres so far."

Not impressive: I check at my Timex and realise we've been maintaining turtle speed - five kilometres per hour.

Behind us, the Wa sweeps down from high terrain and slithers left and right, up and down, through the valley. On both sides is a high curtain of rainforest.

Originating in the rugged frontier between Thailand's Nan province and Hongsa in Laos, the Wa threads across 100 kilometres, through 534,000 acres of the Phu Kha and Mae Jarim wildlife reserves.

Those reserves were once home to the "communists" that the Thai government loved to hate, the militant college students who'd retreated from bloodied Bangkok in the 1970s.

Surachai Chanthimathorn, Caravan's frontman, and Jaturon Chaisaeng, now a leader of the red shirts, were among those who fled from the dictators and lived among these isolated mountains and rivers.

Some died of malaria. Others were killed by soldiers, and their bodies were abandoned in the wild, giving rise to spooky tales for modernday hikers.

It's said that when the first "water runner" tried out the Wa with his inflatable boat 20 years ago, the locals laughed their heads off. Used to only bamboo river craft, they couldn't understand how a balloon boat was supposed to get past jagged rocks and pointy logs.

This "balloon" was tough enough, though, and the stranger had the last laugh. He navigated the course and spread the word, bringing many more thrillseekers to Nan.

The rapids have since been categorised from thrilling Class III to extreme Class V, making the Wa one of the country's best whitewater destinations.

"Watch out!" someone shouts as we approach the Huay Dua rapids. Adjusting his position on the tail of the boat, Captain Tin steadies the raft and studies the stream ahead.

"When I shout, 'Left', those on the left have to paddle very hard!" he hollers. "Same for the right. That's how we'll get away from the nasty whirlpools."

The directions presume that you have a hardy crew - and a lot of luck. Another stone's throw away are a leaping, twisting "Wild Ghost" rapids, just to make sure no one gets bored.

Tin warns us the thrills (meaning severe challenges) will come in quick succession, with the possibility of a 100metre freefall if we don't get it right.

"You'd better tell us when to jump!" someone tries to joke as the nose of our vessel turns toward the froth.

The first raft darts into the rapids and is quickly heaved into the whirlpool, the spinning water sucking hard. But the industrious paddlers manage to escape maelstrom's grip safe and sound.

The second boat is hit even harder and a tugofwar ensues between men and nature, with the men coming out on the bottom - literally. The foam flips the raft over, treating everyone to an unscheduled swim.

"The water pulled my pants off!" Bod cries as he clambers ashore and sits shivering in his skimpy underwear. "It happened so quick! One second you see the boat drop into the cascade and the next the water is everywhere around you."

Beyond the anxious current, the day eases by just like the scenery. We float silently and soak up the feeling, occasionally jumping into the Wa to cool off, acting as if we haven't had enough already.

Before nightfall we come across three more difficult rapids and escape them after a desperate fight. Only then can we pitch our tents on the sand of the riverbank. Food is cooked and the moonshine uncorked.

Once back on the Wa again on the second day, we glide into lower and rockier terrain. The stream is sometimes obstructed and sometimes shallow, making for a nasty paddle. Like rodeo cowboys on a Brahma bull, we keep bobbing up and down.

It gets even grimmer at the Ton rapids - ton means "jump" in the northern dialect, and that's the only word needed in this part of the story.

The rapids look fine to me, but that just demonstrates my naivety. The water flows left, then makes a sharp right turn around a pile of rocks, and finally leaps into the lower swells. Easy, I think: You paddle hard left, then right, then speed up into the gentle part.

Alas, the problem is not entering the rapids -it's getting out at the other end.

Once you've finished bobbing through there's a big "black hole", hidden by the curtain of water. The captain shouts, "Left!" and for a few seconds I see half the raft hanging in the air over the big drop.

Before I can holler, "Dead fall!" we flip up to the left and three of the seven on board - including me - are invited in for a swim.

"Watch you head - you're heading into the wall!" everyone's yelling, the warning echoing off sheer rock.

Tor, a fellow paddler, grabs me by the lifejacket in the nick of time, saving me from a broken nose, at the very least.

"We got you!" Tor shouts, observing with understatement that we seem to have underestimated these notsoinnocent rapids.

"We didn't see the drop beneath the water, so we're trapped in the whirlpool."

An hour later we lumber onto the soft bank again, blessings all round for terra firma. The middle section of the Wa River ends here, and so does our 80-kilometre adventure.

The river gets smaller and smaller as our truck leaves it behind. From the last mountain summit within view, it looks like a meandering train far in the distance. We're all raving about having escaped certain death and comparing souvenir cuts and bruises.

I'm already thinking of returning to the Wa, to the upper section, where whirlpools and waterfalls offer to hold you underwater, right down on the riverbed, all the way to Christmas.

Adrenaline is addictive, and you always come back for a bigger dose.

If you go …

The best time for river rafting on the Wa River is from September to January. Call the Tourism Authority of Thailand at (054) 521 118.