A friend of mine, Christina Campbell, who has done a lot of pretty serious diving came back from Cocos a few years ago and raved about it, so I called my trusty Agent, Jan, at Sure Dive who efficiently tailored an itinerary for me.

The trip out was hairy, but I survived the worst that United had to throw at me - like reassigning my row as smoking after a stopover in Mexico City. A scant 48 hours after leaving London I climbed aboard the Okeanos Aggressor at Punta Arenas.

The cruise out to Cocos is a long, and often rough one. But 36 hours later we woke to the sight of towering cliffs, and tumbling waterfalls. Cocos has a colourful history - it was an old Pirates' haunt, and reputedly still hides millions in gold bullion, but a single glance at the terrain tells you why little of this wealth has been recovered.

If you ever get the chance, and fancy a day off from diving, the hike up to the summit is an easy five hours, and is very rewarding- and there are no mosquitoes!

Cocos's beauty is literally in it's isolation - visitors run only into the hundreds annually, with no permanent settlement . It is because it is so isolated Cocos has escaped a lot of pressure from the fishing industry - as well as attracting lots of pelagics who come to breed, or maybe just to hang out. The island was declared a national park by the Costa Rican government in 1978 but ecological pressures in the form of illegal fishing mount. I hope it is allowed to remain a jewel in the Pacific.

We acclimatised ourselves to our new surroundings, and shook out our kit. The next seven days saw some superlative diving - I understand why the people in the know rate this as one of the best dive sites in the world.

We were promised a shark on every dive - heard that one before? Well, Mario, the dive master, wasn't exactly out on a limb on that one- they were everywhere. Schools of hammerheads coming in to cleaning stations, squadrons of manta, marble and eagle rays, white-tip reef sharks carpeting the rock, even inquisitive turtles that paused to say hello. And occasionally, as you hung in blue water, a silky coming in to check you out.

Cocos doesn't have a fringing reef as such - just a few patches of staghorn here and there - in the main the bottom is sandy or rocky - ideal for anchoring photographers provided you avoid the copious population of urchins. I've never so much as touched a camera underwater, but I quickly adopted one of the boat's Sony Hi-8s, a really easy alternative even in my amateurish hands - and allowing replays minutes after each dive - "There - look - it was a Silky circling behind you, Mark". And then I decided to give a Nikonos a try.

How often has a skipper told you that there "was a whale shark here last week? Well, there had been, and it came back for more. Our week's highlight coincided with my first ever still camera dive - a beautiful young 16 foot whale shark; what better subject could I ask for?

I was lucky enough to share the boat with a marvellously laid back bunch - Jim Flasar - the "Ship's Vet" (I still carry antibiotics marked "for use on cats and dogs only"), Mark Williams, who along with Jim passed some superb photos on to me, Andrew Dawson, Merrillee Fiedler, the "Mexicans" and our "Tico".

I cannot close without mentioning the superb crew - helpful and friendly to a man - The Okeanos is renowned as one of the shabbiest boats in the Aggressor fleet, but fortunately it has one of the best crews!

This is the dive destination against which to compare all others.

Pictures:
Scalloped Hammerhead - © Jim Flasar 1996
Turtle, Eagle Ray & Me with Hi-8 - © Mark Williams 1996
Whaleshark - © Peter Strong 1996