Into the depths of Isla del Coco

The first group of hammerhead sharks came straight towards us. They were three to four metres long and their approach caused us to take cover behind some over-hanging rocks 25 metres below the surface. Soon thereafter, a shiver of about 50 hammerhead sharks passed directly over us, no more than a few metres away. We remained motionless and held our breath. Within a few moments we were surrounded.

It was a sight that commanded our respect. Their massive grey and white bodies moved like a slow torpedo while their black eyes scanned the deep blue depths of the ocean.

When we were sure they had gone we left our hiding place and swam towards a rock-shelf where roughly
ten reefsharks lay. The reefsharks regarded us sluggishly and seemed unfazed by our invasive presence.

During the first few dives I felt apprehensive even when at a fair distance from them. But after a few days in their environment and after seeing hundreds of them, it was only when their long bodies brushed against me that my uneasiness reawakened. Aside from that, I had calmed myself.

When we were up close, the sharks came alive and their bodies became rigid and filled with alarming force. Their yellowish green eyes looked at us threateningly and I backed off carefully away. You can never be completely calm around these tigers of the deep.

The treasure cove

Few places on earth have such an enormously rich marine life as does Isla del Coco, an uninhabited tropical island 500 kilometres south-west of Costa Rica. It is better known as Treasure Cove Island. The first pirates came here during the 17th century to gather supplies in preparation for their next raid along the South American coast.

According to legend, the pirates also hid gold and precious stones worth a fortune on this island. However, not one of the hundreds of treasure expeditions has found so much as one gold doubloon.

The real treasure I discovered are the warm, turquoise waters surrounding the island as well as the animals and plants unique to Isla del Coco.

"You can't compare this island to anywhere else in the world," says underwater photographer Jay Ireland
who has dived all over the world for over 30 years. "Cocos is number one for me. There is nowhere else I have swum with hundreds of hammerhead sharks around me, not to mention whale sharks, giant manta rays,
sea turtles and dolphins that often appear in a single dive.

There are unprecedented numbers of species here and the most surprising is the amount of them," says Ireland.

Hammerhead sharks in full force

Isla del Coco is one of the few places in the world where hammerhead sharks assemble in the thousands. They come to clean themselves. Most dives are done near these cleaning stations which often lie 30-40 metres below the surface. Here, hammerhead sharks stop to let small fish clean away parasites and dead tissue.

Scientists also believe hammerhead sharks are drawn to the island to breed and that could be why they gather in such large flocks. Another theory is that Isla del Coco is a half-way point in their roaming through the Pacific Ocean.

Because the island is a national park, some divers live on board the boat during the 10-day trip. The actual diving takes place from Zodiacs or small aluminium boats. The number
of divers on each boat is usually around 20 and there are an average of three dives a day. Those who are not worn out after three dives are offered a night dive.

Hidden treasures

While waiting for the next dive you can embark on a treasure hunt or bathe under one of the 200-odd waterfalls on the island, which is an unforgettable experience. Early one morning we came ashore with the Zodiacs. The high waves made it necessary to swim the last stretch to reach land.

Once we had gathered together, we started into the jungle and began our hike to one of the waterfalls. It is hidden by dense tropical foliage and it is easy to let your imagination take over. Every cave you see seems to be the ideal hiding place for a hidden treasure chest.

On the larger rocks, seafarers carved the names of ships and short messages. 'Cousteau' is one we found. Arrows and mysterious symbols are carved into others. After half-an-hour of hiking along a jungle brook, we arrived at a cliff wall where a waterfall was cascading down from a height of 60 metres. The water was wonderfully cool and refreshing.

While we rested under the falls the guide began telling us how gold fever changes people. The story concerned a man by the name of Gissler, a German who in the early 1900s lived on Isla del Coco with his American wife.

For 20 years they searched for hidden treasure before giving up and returning to the mainland. Gissler later died penniless in New York City, never having succeeded in discovering so much as one gold coin.

Fearless mantas

Of course it is exciting to experience Isla del Coco as an old pirates' island. All that fades away, however, the minute you enter the water. During one of my dives with my diving partner, Randy Johnson from Alaska, nicknamed 'Ice Man', we were approached by 12 large mantas.

We adapted our weights and hung motionless just under the surface while they calmly swam under, over and between us just a few centimetres away. We could see traces of parasites on their bodies, small sores and even, swimming around them, reef-fish who help to heal the mantas' sores.

I found the diving to be more valuable an experience than any treasure of gold! When we later surfaced, we were told by the driver of our Zodiac that mantas often follow the rubber boats and they like to stay close to them.

In good hands

To live aboard a boat, such as Undersea Hunter or Okeanos in the middle of the Pacific Ocean with 15-20 other divers for 10 days is an intense experience. Everyone has something fantastic to recall about their dive. Free time is spent exclusively preparing for the next dive; cameras are cleaned, batteries charged and film is developed. Even though every dive involves contact with sharks in their hundreds, attacks are rare.

The crew onboard instruct divers to not touch the sharks even though they come so close to you it can prove tempting.
"I have witnessed one or two accidents where a diver was attacked by reefsharks but it has always been the diver's fault," says divemaster Mario Vargas who has been diving around Isla del Coco for almost 10 years.

He explained that it is inviting to touch the sharks when they come so close, but you're asking for trouble if you do. Reefsharks especially, which can measure up to three metres long, usually ignore divers, but if someone touches them, they are aggravated to bite. Most often it is a bite on the hand and the attack is over. He went on to say he has never witnessed a hammerhead shark attack.

Divers are certainly more respectful of them. Undercurrents surrounding Isla del Coco can betray a diver. To try and swim against them is useless and you have to keep relatively close to the shoreline when diving. If you lose sight of the coastline it does not take more than a few minutes before the undercurrent drags you out into the Pacific Ocean. The crew, however, is experienced and know where they should look if a diver does not come up at the agreed time and meeting place.

Powerful up- or downstreams are also common. They are caused by deep ocean currents that collide with the coast. In no time at all, they can drag a diver with them. During one dive I was sucked into a climbing stream and before I managed to react by shifting my weight, it had carried me into a cliff wall where 20 or 30 needle-sharp sea urchins awaited me.

Without seeing them I put my left hand right on their spikes and screamed a silent bubbled yell. I was only really worried when I saw blood seeping out of my glove because I thought the reefsharks near me would be attracted by it. Luckily they were not feeling peckish at the time!

Isla del Coco is an island of cliffs and all dives are along the coastline. The bottom is made up of fine combed sand and sharp cliffs of volcanic origin. Visibility varies between
25-50 metres. It lies five degrees north of the equator so a thin wetsuit is enough to keep warm.

Divers who expect warm tropical diving with corals will be disappointed. Most of the coral was carried away by El Nino, a warm ocean current which regularly pulls in towards the South American coastline. For visitors, Isla del Coco is an oasis both under the surface and on land.

The pirates have of course left the island but the wealth of flora and fauna remains. And perhaps somewhere, far from the treasure hunter's grasp, lie a few gold doubloons.

Frank Stenstrom is a Karlstad-based freelancer.