Going wild in Costa Rica (+photos)

Cruising the Rio Tempisque, river boats offer wildlife enthusiasts plenty of opportunities to sight animals and birds. Photo / Supplied

At the edge of the Pacific, where the Tarcoles River meets the ocean and route 34 breaks from the mountains, there is an infamous highway bridge. People come from miles around to see the crocodiles beneath.

Stumbling from our "Tourismo bus" our guide shouts, "Heeey you bad boys, you want cerveza? Imperial is good, yes? Here, eets for you!" He tosses his half empty beer can over the guardrail. On a sandbank 7m below clunk! Fizz! Nothing! Like sodden grey logs they lie there with their mouths wide open. The sandpipers skitter between picking fetid shreds of decaying flesh from their jaws.

Litter is an obscenity, especially as Costa Rica's economy depends upon a pristine environment, so I am tempted to retrieve the can. But better judgment prevails.

The appearance of relaxed indifference is purposeful. Wound tight as a steel spring, an apparently dozing crocodile can explode into a deadly blur of snapping jaws. A large dog bites at 100 PSI (pounds per square inch); a crocodile delivers a bone splintering chomp at 3000 PSI.

Thick reeds line the shore and somewhere within, Tyson, a local celebrity, lays waiting. He is said to be at least 6m in length and on a number of occasions has invaded the nearby town on dog-snatching forays.

For those who come to experience the wildlife, Costa Rica's rivers provide the most immediate transition from urban bustle to rustic paradise.

Many seek challenging wilderness adventures while others are just happy to ride a river boat through the local mangrove swamp.

The crocodiles are an endless source of horrified fascination. The muddy estuaries and placid channels are also a bird-watchers paradise. And there is some amazing whitewater rafting. There's great whitewater rafting in New Zealand, of course, but it doesn't have the added frisson provided by all those crocs, so before heading down the Pacuare River we pay close attention as Mauricio, our pilot, clips my wife Maggie's life jacket together.

"This is very important; it is the only thing that stops us drowning if we fall out. In the river we keep our feet downstream and we stay happy."

With naivety and innocence we push our flimsy little boat out into the current.

At the upper end of the gorge, with a watery slurp, our boat is sucked into the rocky gullet. It is pure whitewater heaven. We are irrevocably committed to 31km of jungle-shrouded canyon.

Jelly-green water is pounded into foam amongst bus-sized boulders. In the jaws of "Cimarron", an especially ferocious rapid, Maggie is tossed from her floppy rubber perch at the back of the boat. I watch in horror as her orange helmet disappears beneath the froth. She surfaces briefly and Jose Pavlo, in the accompanying safety kayak, noses toward her. "Look at me, Look at me", he screams, "Grab the boat!"