IT‘S JUNE, and the temperatures in Europe are climbing as high as 35°C. Sitting in the office and wiping the sweat from my brow, I am reading the sad news about abnormally high ocean temperatures this year.
The El Niño warm cycle has been affecting the southern Pacific significantly, as well as other areas around the globe. As sharks generally like colder water, there is a serious threat that our August trip to Cocos targeting sharks might fail. I close my eyes and look into the blue water, seeing the imagined school of hammerheads disappearing rapidly into the distance.
Earlier in the year, I had been alarmed to hear about an increase in illegal fishing around Isla de Coco. The news about El Niño is another hit below the belt. As a wildlife photographer, I know how volatile luck can be.
But I also realise that strong belief is an important component of success. Furthermore, luck simply looks for an optimist on whom to settle: “The path is the goal,” says the Buddha. Repeating these words, I manage to rematerialise the school of hammerheads.

On 9 August, after 18 months of waiting, we are finally on our way to Costa Rica. Two flights and two nights in hotels in New York and San José, followed by a 32-hour boat-crossing, await us.
We have planned the liveaboard trip for the peak of the rainy season. Lower water temperatures are supposed to make this the prime time to spot hammerhead sharks, although there is a price for this, in the form of rain, wind and rough seas.
The van driver who is taking us from Costa Rica’s capital San José to the port of Puntarenas, recommends that we stop at a pharmacy. Thirty-two hours of swaying on the waves with an inverted stomach will be easier with medicinal assistance.
The crossing seems endless. The sound of the engine is occasionally drowned by bells summoning guests for meals. Only a few strong individuals respond to the calls. Since the seasickness epidemic broke out, meals tend to go straight overboard.
Around midnight, the engines finally subside. Reaching the calm seas of Chatham Bay was the rescue we all desperately needed.

“Wake up!” As divemaster José Manuel knocks on cabin doors, I am patiently preparing my camera, housing, lenses and cables.
The check dive is at Manuelita coral garden, where 25m visibility is a nice surprise. There is little growth, but then, corals are not why we‘re here.
I constantly keep an eye on the blue, expecting something bigger to show up. Whitetip reef sharks are around in big numbers. Some lie on the bottom, while others search for prey between corals.
Two hammerheads are checking out a new group of divers. Their movement is unmistakable. They undulate more than other sharks, to let the eyes placed on both sides of the hammer monitor the area ahead, behind and on both sides, all at once.
This is not the only advantage of these sharks’ strangely shaped heads. Only recently, scientists discovered that they act as detector as well as compass.
By receiving electromagnetic waves, hammerheads sharks can detect animals hiding in the sand, and by picking up geomagnetic impulses they can navigate on their migration in the golden triangle formed by Malpelo, Cocos and Galapagos.

Sharks are mostly night-hunters. Although their vision works well in the dark, the whitetips around Manuelita have learned to use dive lights when hunting. “We‘re trying to find a parrotfish, snapper or bannerfish, light it up and wait for sharks to do the rest,” says José Manuel.
Sharks are here in force, expecting divers to help them to find their prey. The hunting has begun. It isn‘t long until Manuel’s shaker signals that the bait has been spotted.
The parrotfish is aware of the danger, and hides back among the corals. However, its movement has been noted by many sharp eyes. Grey bodies start scanning every recess, every rock, every overhang – there is no place to hide.
The sharks speed up their moves, swirling the sand until they find the parrotfish. Crowd psychosis takes over. Soon the winner swims out from the sand cloud, carrying the ragged fish in its mouth.
As we watch the show for a third time, a new player arrives on the scene, obviously one in a different weight category. A combination of shaker and flashing light make me lift my head. A huge striped body emerges from the dark. Tiger!
Spotting such a creature at night boosts the adrenalin level quite a bit. A few weeks ago, we learn later, this shark joined in with the action aggressively, cutting a whitetip shark
in two. This time he checks out the divers and disappears into the night.
A minute later the same scenario is repeated with another big player – a Galapagos shark more than 3m long. It’s my best night dive, by far.

It‘s raining again. Thick fog comes down from the island. Rangers from the conservation organisation Marviva are leaving the bay to patrol.
On the morning dive on Big Dos Amigos, we had spotted a fishing boat. Cocos has always been a target for illegal fishing, and it’s down to the work of Marviva and rangers from the national park that its waters remain so rich.
Swell, mist and rain accompany us on the short boat-ride to Dirty Rock. Light conditions are far from perfect, but the dark blue surface is a good sign.
In the past two days we have grown familiar with the place, so after the usual back-roll entry I head straight to the cleaning station.
Barberfish (Johnrandallia nigrirostris) care for the hygiene of bigger animals here, and are the only reason why pelagic shark species such as hammerheads come close to shore.
Thanks to the great visibility, dark shadows are visible from the surface. What I see pulls me straight down, unwilling to wait for anybody else.
Hiding close to the bottom in 38m, I seem to be holding my breath. They are everywhere. No word describes the next 20 minutes better than “trance”.
There are hundreds of hammerhead sharks, coming close in dense formations, back and back again. I can feel my heart pounding. My hands are shaking, and I simply don‘t know where to point the camera.
When my computer tactlessly informs me that my no-deco time is over, I ignore it. No-deco dives are the main rule on our boat, but the rules don’t count now. I’m staying.
Five more minutes, please!

Cocos Island is five miles long and two miles wide. It’s the tip of a volcano situated in the eastern Pacific 300 miles south-west off the nearest shore point, Cabo Blanco. Because of the 200in of rainfall it receives, the island is covered in dense rainforest, with a tangle of rivers and creeks creating numbers of waterfalls.
Although the shores of Cocos seem too steep and inhospitable, there are animals content with the protection it affords. The noise of the wind and sea is compounded by the screech of hundreds of boobies and frigate birds.
From Wafer Bay, the land trail leads next to the ranger station, then over a bridge constructed using only confiscated fishing material to end by a beautiful waterfall. Nobody refuses the chance of a freshwater bath and torrential massage.
On our way back, the rangers show us a 2-ton pile of thick lines, sharp hooks and buoys fitted with radio transmitters, the result of four months of work.
The radio buoys cost US $7000, they tell us, and fishermen are ready to take big risks to bring in a valuable catch – shark fins in this case. The Asian shark-finning mafia has hit Costa Rican waters like a cancer.

The weather doesn’t play along, but based on previous experiences here, the combination of dark sky, swell and rain might be a sign of good action to come, so no one complains.
The reef top is at 25m, and is marked by a buoy. The relatively flat bottom here offers few opportunities to hide from the current, and swimming to the most current-exposed tip is a battle.
On the way, we meet marble and eagle rays, tons of whitetips and a big school of jacks. Although any of these individually would normally have me spending a long time with the camera, here on Alcyone it‘s just a warm-up.
On the tip of the reef, we stay anchored in 35m to watch. The view is filling up with shark silhouettes, and now I see that this place is further testament to the healthy hammerhead shark population. This is the hammerhead wallpaper of which I dreamt back home.
Yet the dive is not over. We are drifting above the reef when, suddenly, a big shadow appears. Whale shark!
A 7m youngster heads straight towards us. We try to swim alongside it, until our computers exile us back to the shallows.
Later, I am eagerly browsing the images I took on this wonderful dive when suddenly, believe it or not, another whale shark swims towards me. This one is at least 12m long. It can’t be true!
There will be many such beautiful moments to dream about during the 32-hour crossing back to Puntarenas.

GETTING THERE: Fly to San José in Costa Rica via major US airports
DIVING: Undersea Hunter, www.; Okeanos Aggressor,; Wind Dancer,
MONEY: Rican colones, US dollars, credit cards
WHEN TO GO: Year-round, the rainy season (June-December) being reckoned best for shark sightings.
PRICES: An 11-day cruise (seven days’ diving) including land transfers and nitrox costs £3000 with Undersea Hunter. Continental Airlines flights from London Heathrow via Houston to San José cost from £540.