ONE OF MY FAVOURITE DIVE SITES in Cocos Island’s waters must be Roca Soucia or “Dirty Rock”, so-called because the small part that breaks the surface has been a roosting point for boobies for centuries.
It’s an interesting spot because the currents that push round it attract all manner of pelagic fish. There has been something different there every time I’ve dropped in.
While there I have photographed whale sharks, massed schooling jacks, mantas, the large marble rays that are almost ubiquitous in this part of the world, mobs of whitetip reef sharks and, of course, schooling scalloped hammerheads.
Terry Fisher, the engineer from Ambient Pressure Diving, had never dived outside British waters before, and I’m afraid he might have been spoiled by the trip to Cocos that he took with me.
We dropped in for our last dive at Roca Soucia, armed with our rebreathers and hoping for a close encounter with any of the above, and were pleased to find ourselves on a cleaning station with a few Galapagos sharks getting a manicure.
I hid behind a turret of rock and managed to get off a few pictures of these lovely-looking, large, fast-swimming, streamlined sharks. I did this by popping above the parapet from time to time as they circled, and it was only when we were joined by a group of conventionally equipped divers, who didn’t feel that it was necessary to hide, that the show was over. Well, it was their holiday too!
Rebreather or open-circuit divers, none of us are invisible under water. The CCR merely affords you the luxury of ambush without your exhaled bubbles giving away your position.
People always think of Cocos as the place to see schooling hammerheads, and it is, but there are far more animals to catch the eye of the photographer, and you soon grow tired of attempting to get close enough to the skittish schooling sharks.

IF ANYTHING, COCOS is the land of the whitetip reef shark. These appear to be almost as common here as anthias might be in the Red Sea.
Large marble rays are almost as frequently encountered, and it’s relatively easy to get a photograph of the two species lying side by side during the daylight hours.
At night the little sharks turn into voracious hunters, and it’s bedlam down there as they compete in great packs in the dark to flush out unfortunate prey from between the rocks.
Alcyone is a sea-mount discovered by Jacques Cousteau and named after the vessel he was using for his Cocos expedition all those years ago. You need to drag yourself down a fixed line from the panga against a ripping current, but once you’re down it’s relatively easy to take shelter among the red rocks, joining plenty of large almaco jack (the biggest of the jack family) and squadrons of other fish such as yellow and gold snapper and yellow-tailed grunts.
Some of the largest whitetip reef sharks lie about lethargically on sandy patches between the rocks and, provided you’ve got time, it’s relatively easy to approach without disturbing them for the close-ups.
Then it’s slowly back up the line in that ferocious current with all sorts of animal encounters still waiting.
I photographed some schooling horse-eye jack that conveniently came within range of the line, while our dive-guide went drifting off in the flow in an attempt to get some pictures of an untidy group of common dolphin that cavorted around us temptingly.
I say temptingly because should all of us have left the line, the panga driver would have had a merry old time searching for us later at the surface. As Terry observed when he first saw the Pacific Ocean: “Big, isn’t it”
Every dive in Cocos is different but equally eventful. Stan Waterman, that grand old man of diving who has been to Cocos more times than some of us have had hot dinners, once opined that Cocos “always delivers”.
It’s a lonely outpost 350 miles off the coast of Costa Rica, and a place where cold upwellings bring nutrients and deepwater sharks up close to the surface.

THESE UPWELLINGS CAN PLAY havoc with your photography. With surface water temperatures at around 26°C and the temperature at 30m around 14°C, the mixing zone in-between can cause a lot of refraction of the light, making it very difficult to get sharp pictures.
It’s not all about big fish, either. I had a lot of fun photographing the barber angelfish that clustered under the great arch at Dos Amigos Grandes (that’s the bigger of the “two friends” that form a pair of isolated rock outposts off the shore at Cocos itself).
These little fish are confused. They gather close to the rocky underside of the arch and swim the wrong way up. Well, nobody said they were clever!
Lobster Rock sounded inauspicious during the dive briefing. You go into and swim out across the current over the sand looking for batfish.
These may not be the sort of batfish you expect. These batfish look less like table-tennis bats and more like the type of animal you might find in a belfry.
Terry and I were abandoned for a time by our guide, who told us to wait at the bottom of the rocky substrate that forms Lobster Rock while he grouped the other divers.
You may know that it’s possible to talk through the mouthpiece of a rebreather, and I asked Terry what we were waiting for. He didn’t understand, so I got closer. Eventually I had him in a close embrace while I attempted to enunciate in his ear, and it was at this very moment, as I held him close, that a huge shark swam by.
“Tiger!”
He knew what I meant but it was too late to deploy my camera, which by now was wedged between us against the effects of the current. That’s Cocos Island. Anything can swim by. I had to content myself with photographing the snapper that were piled up in the tight gaps between the rocks.

WE TRAVELLED AND STAYED aboard Sea Hunter, part of the Undersea Hunter fleet that also includes Argo.
Sea Hunter is not a beautiful vessel, but it’s a great tool for the job. It’s comfortable with its twin engines and has great sea-keeping qualities that one might come to appreciate during the 36-hour crossing from Costa Rica. It’s a fantastic dive platform.
Avi and Yosi, the Israeli owners, are keen divers and run their fleet with a passion that reflects this. Avi has been an enthusiastic rebreather diver ever since he first used a Mk15, and the dive vessels are extremely closed-circuit friendly.
Over the years I’ve been privileged to make six trips on their boats. It’s not always the same under water, but it is always good.
I went to Cocos with Terry primarily to experience the recreational version of an APD Evolution rebreather which, at Rec1 level, was limited to only 18m deep.
That may not sound much, but around Manuelita Island, a satellite of Cocos, there are plenty of shallow if dramatic dives that we were able to enjoy before we changed the software to Rec2 to go deeper.
I remember one previous trip when I was doing a first weight check-out dive next to Manuelita, and trying to photograph the schooling hammerheads while an eagle ray was jammed between my legs.
Because you are dealing primarily with pelagic animals, it’s difficult to anticipate what you’re going to see, but you can certainly anticipate seeing something good in Cocos!

DeepSee
Argo is bigger than Sea Hunter and carries something special in its moon-pool at the stern. This is the DeepSee research vessel, which is capable of diving deeper than 300m.
When not being used for research it’s available to take tourist divers for a ride. The trip is expensive (around US $1800) and takes up most of half a day, but it certainly is a once-in-a-lifetime experience.
Two passengers and a pilot sit inside a hemispherical bubble. Before departing, the passengers are briefed as to what to do should the pilot unexpectedly die during the trip, and also what to do should a fire break out on board. It certainly concentrates the mind.
Our young pilot assured us that he was feeling in the best of health before we set off.

FACTFILE
GETTING THERE Fly to San Jose, Costa Rica, via Newark in the USA with United Airlines, or go via Madrid with Iberia.
DIVING & ACCOMMODATION mv Sea Hunter has twin-berth cabins with en suite facilities, www.underseahunter.com.
WHEN TO GO Any time
MONEY US dollars and credit cards
HEALTH The nearest hyperbaric chamber is at least two days’ sailing time away, so no decompression diving is allowed and long safety stops are suggested.
PRICES Scubatours Worldwide offers a 10-night trip to Cocos on Sea Hunter, including flights from Heathrow, transfers, departure tax, marine park fees, two nights in San Jose, full-board on the liveaboard and seven days’ diving with nitrox for £4044, www.scubascuba.com
FURTHER INFORMATION www.visitcostarica.com