Diver with a lone barracuda.

I HAVE NEVER FORGOTTEN the astounding visibility of the waters around Little Cayman. At Bloody Bay and Jacksons Point, the reef top descends sheer and sudden into the abyss, and the clarity of the big blue is dizzying.
This small island - a hundred miles from the cruise ships, burgeoning hotels and rapidly breeding condominiums of Grand Cayman - was spared from the ravages of Hurricane Ivan in 2004, but
I was anxious to see if the reef was as vibrant and rich with marine life as it had been seven years ago.
At the Southern Cross Club, Little Caymans classiest resort, first impressions were reassuring. The clubhouse retains its friendly self-service honesty bar, and there are still only 14 recently refurbished suites, all facing towards the sparkling Caribbean Sea.
Joining the dive-boat for the regular two-tank morning dive, I found that all the other five divers were repeat visitors to the resort. Thats always a good sign for hotels and dive sites.
And under water, the reef was just as dramatic as I remembered it. Elephant ear sponges, giant barrel sponges, elegant sea fans and coral whips protruded from the wall.
Orange basket stars snaked their long spidery tentacles across the corals and Nassau groupers came nosing towards me, hoping to use me as cover while they sneaked up on unsuspecting wide-eyed squirrelfish. To the casual observer, things under water at Bloody Bay were just as they should be.
And yet, it is a sad fact that coral reefs within the Caribbean have seen an overall decline of live coral cover of around 80% in the past 25 years.
I had heard reports that nowhere in the region had been spared the ravages of some degree of coral-bleaching, and had read reports in the science journals about sinister diseases that were infesting the reefs.
Bloody Bay was one of the first designated marine reserves in the region, has been protected since 1986. Fishing is carefully controlled and lobster and conch populations are healthy.
With only 150 full-time residents, Little Cayman remains a tranquil island where nature is allowed to follow its course relatively undisturbed.
On land there are iguanas, and at Governors Pond a large breeding colony of red-footed boobies do all the hard work for a population of frigate birds that mob them as they return
from a hard days fishing at sea, making them disgorge their catch so that they can steal it.
Recently, Little Cayman has become home to a new reef research facility, the Central Caribbean Marine Institute. Built and created as a non-profit facility, it has already forged relationships with some of the top marine science faculties in the USA and Europe, and persuaded HRH Prince Edward to become its patron. Last year, it welcomed the first visiting students and began to offer a dive with a researcher (DWAR) programme for sport divers wanting to learn more about coral reef ecology.

DR CARRIE MANFRINO, AN ASSOCIATE PROFESSOR at Ruttgers University, is Research Director at CCMI, and she welcomed me on a tour of the facilities. As we viewed the wet-lab, the library and capacious dormitories and dining areas, she explained why Little Cayman had been chosen as a home for the institute.
The reefs here are probably the best in the whole Caribbean, with over 350 fish species and several dozen species of coral, she said. Right on our doorstep weve got a shallow lagoon and the really deep ocean - so that we can see a broad range of megafauna, including eagle rays, sharks, grouper and turtles.
But, before I could breathe a sigh of relief, she continued: The authorities here have done a fantastic job of protecting the reefs, but the corals are still suffering through globally raised water temperatures, and weve seen evidence of white plague.
To see what she meant, I was offered the chance to dive with Professor Vania Coelho, whose students have been carrying out a highly experimental form of treatment on the disease.
Under Vanias guidance, I was able easily to distinguish the difference between coral-bleaching (a sign of general stress) and white plague.
Whereas bleaching tends to be most obvious at the tips of a coral, the plague syndrome is more generalised and manifests as a creeping patch or band of white on the colony.
The treatment involves scraping away an area of diseased tissue and a small area of healthy tissue to create a kind of a fire-break on the surface of the coral. The plague is caused by a bacterium, and the researchers have experimented with sealing the bare area with a kind of marine epoxy. If applied correctly, the epoxy seems to be able physically to block the bacteria from spreading to the rest of the colony.
This is a kind of Band aid solution, Vania explained, but corals are under so many different kinds of threat right now that I believe we have to try anything that will allow them to live a while longer.
Dr Manfrino received some extremely good news during my visit. She explained that though Little Cayman had seen a decline in the numbers of colonies of reef-building corals between 1999 and 2004, since then the decline had stabilised - something not seen in most of the rest of the Caribbean.
We see five major genera at Bloody Bay that make up 90% of the corals around the island. These corals are the most important reef-building corals - and they are all recruiting, establishing and surviving, she told me.
It is this kind of discovery that makes Little Cayman such an important centre for reef research. Theres no point saving the fish in a marine reserve if the reef dies, Professor Coelho told me on the boat as we made our surface interval.
Thats like trying not to shoot birds in a forest but cutting down all the trees - the birds have nowhere to live and to breed, or anything to eat!
On almost every dive at Bloody Bay Marine Park I saw green turtles, several Caribbean reef sharks and always at least one friendly grouper.
Jan, a diver from New Jersey, explained to me in the restaurant one day that he was particularly fond of these fish. I wont eat grouper now - even though its delicious, he said sheepishly. When youve had one of those groupers here come right up to your mask and wait to be tickled, you couldnt possibly eat one ever again.
For many divers, it is the easy-to-spot and charismatic undersea creatures that make for good diving.
I agree, but perhaps with a little more training we can learn to be just as interested in corals, the building blocks of the entire reef.

Meeting the celebrated Jerry, the friendly grouper.
Typical coral scene on Bloody Bay Wall.
Tube sponges.
An epoxy strip is sealing the healthy section of this Diploria brain coral from the part on the right infected by white plague
on this Montastrea cavernosa the grey area is dead and the plague is advancing by 1cm every few days
distinctive discoloration of dark spots disease on a brain coral


GETTING THERE: British Airways flies to Grand Cayman four times a week from Heathrow. Take an inter-island Cayman Airways flight to Little Cayman.
DIVING & ACCOMMODATION: Southern Cross Club, www.southerncrossclub.com. The Central Caribbean Research Institute will be running Dive With A Researcher (DWAR) programmes at various times during 2008, www.reefresearch.org
WHEN TO GO: The dry season runs from November-April, the wet season from May-October. Hurricane season is from June-November.
MONEY: Cayman dollar
PRICES: Seven nights full-board accommodation plus transfers at the Southern Cross starts from US $1775 (two sharing). A week of two-tank day dives costs $485. Return flights with BA to Grand Cayman start from around 700, Cayman Airways to Little Cayman flights around $130.
FURTHER INFORMATION: www.caymanislands.co.uk