Orange-spine Unicornfish (Naso Lituratus): So called because of the bright orange defensive spine scalpels on its tail, the Orange-spine Unicornfish is seen often in the shallow inner Lagoon and the Reef Crests. Just to confuse matters some fish books call it the Yellowkeel Unicornfish. No matter. The thing to remember is it's the one that looks like Elvis Presley with yellow hair. It has a yellow-edged black mask extending from eyes to snout, a mouth that looks like it has applied lipstick and a black and yellow dorsal fin. A 45 cm grey body and a white tail edged in black complete the ensemble.

Common Octopus (Octopus vulgaris): You'll be lucky if you see an octopus while snorkelling the Reef Crest. Not because it's rare but because of its extraordinary ability to hide in plain sight. Using a network of pigment cells and specialized muscles in the skin, the Common Octopus can almost instantaneously match the colours, patterns, and even textures of its surroundings. Predators such as sharks, eels, and dolphins plus eager snorkellers swim by without even noticing it. Massive bulbous head, large eyes, and eight distinctive arms give it a unique appearance. Under threat it will release a cloud of black ink that both obscures its attacker's view and dulls a predator's sense of smell, making the fleeing octopus harder to track. Their soft bodies can squeeze into impossibly small cracks and crevices where predators can't follow and if all else fails, an octopus can lose an arm to escape a predator's grasp and regrow it later with no permanent damage. Watch out for the beak-like jaw that can deliver a nasty bite and the venomous saliva used mainly for subduing prey. The Common Octopus can grow to about 4.3 feet in length and weigh up to 22 pounds although averages are much smaller. They prey on crabs, crayfish, and molluscs, and will sometimes use their ink to disorient their victims before attacking.

Long-barbel Goatfish (Parupeneus macronema): Recognised by its reddish colouring and thick black stripe running from eye to black dot on tail, the 30 cm Long-barbel Goatfish can been seen feeding on rubble patches aound the dead parts of coral. The workers of the Lagoon, Goatfish are always foraging about on the seabed, their heads buried in the sand and raising a thick cloud of dust. The two long barbels located under their jaws, which give them their name, contain chemical sense organs that enable them to find invertebrates like shrimps or worms beneath the sand. Apart from their chin whiskers, you will recognise them by their streamlined body with two dorsal fins and a forked tail. Goatfish are commercially important because their flesh tastes like shrimp.

Did You Know? Coral reefs are the most diverse ecosystems on Earth. They occupy less than 0.1% of the world's ocean surface yet provide a home for 25% of all marine species including fish, molluscs, worms, crustaceans, sponges and so on.

Giant Moray (Gymnothorax javanicus): The Moray Eel looks vicious but is really a softie (so we are told). It can grow up to 2.4 metres weigh 30 kg and is usually docile. However, it is a canivore and is equipped with very sharp fangs which it uses for grabbing passing fishes. So don't get on the wrong side of a Moray. Usually seen during the day with just its head visible from a hole or gap between rocks, the Giant Moray can be identified by the numerous small dark spots on the head and back. Morays undergo a sex change during growth changing from male to female.

Schooling Behaviour: There are many advantages acruing to a fish when it schools with others whether from the same species or not. When a large fish attacks a school, they scatter like an explosion. This move confuses the predator and the prey escapes. Schooling also improves a fish's chances of feeding. Algae-covered rocks are fiercely guarded by Blue-striped Surgeonfish and by Damselfishes. A single fish would stand less of a chance but a group can succeed by sheer confusion. It is a great sight to watch.

Titan Triggerfish (Balistoides viridescens): Some consider the Titan Triggerfish, sometimes called the Giant Triggerfish, to be the most dangerous fish in the Maldives. That is a bad rep because the normally peaceful Titan, which grows to 75 cm, only gets aggressive when defending its eggs during the nesting period. Female Titans lay their eggs in a shallow depression on the sandy bottom of sheltered inner reef slopes. Male Titans guard them until they hatch. They are concerned about other egg-eating fishes but will challenge anything including snorkellers on whom they can inflict a really nasty bite. However, move away and they will return to nest-guarding duties. Size apart the Titan can be identified by its yellow on black criss-cross body markings, distinctive yellow dorsal and anal fins edged in black, yellow tail fin edged in black and a black moustache streak above its mouth.

Fish-spotting in Biyadhoo: Biyadhoo is a great little atoll just half-an-hour by speed boat from Malé International Airport. It has a stunning reef and good snorkelling conditions. The mornings were very clear and calm with the water like crystal. Huge schools of blue-lined snappers hung motionless on the outer edge of the reef. Cruising in the deep were enormous Trevelleys, reknowned predators just waiting their chance. When they attack, the schools literally explode in all diferent directions which confuses the hell out of the Trevelleys because they have eyes at the side of their head and can’t see clearly straight ahead so grabbing a victim is very much the luck of the draw.

Afternoon snorkelling is different. The tide has changed and while the current isn‘t strong it brings plenty of sand. Plus the sun is no longer overhead but off to one side at an angle of about 45°. The dapples in the waves split the Sun’s rays prismaticaly into weak searchlights that probe the inky darkness below. It’s in these dim realms that many of the big fish dwell but often what you see is a mere glimpse of something big. A vague silvery blue outline – what was that? The imperceptible movement of something big – was that a Ray’s wing?

Damned right it was ! Since a minute later an enormous brown-spotted Eagle Ray swooped up from below and behind (imitating a fighter plane attacking and enemy bomber) and passed underneath me just an arm’s length away. I watched in awe as its highly-lethal tail flicked past scaring the crap out me. It banked gracefully and, Oh No, it’s coming back for another look at me but then decided I wasn’t interesting and disappeared back into the murky depths. The whole contact lasted a mere 10 seconds but, Boy, did they seem like long long seconds.

Among the rocks and corals of the lagoon, the water is shallower and carries less sediment. All manner of exotic fish cruise in, out and around: crimson rock cods, blue surgeonfish, sailfin tangs and here’s a rarity: a brown octopus, or rather a grey octopus, no its a pink octopus. Oh for Heaven’s sake, is it ever going to stop changing colour? It settles for brown with white spots and we observe it for half an hour taking many really clear pics. And just to cap the day off a massive Moray Eel squeezed in between two rocks. He’s looking really photogenic but while Rosmarie lines up the camera we are caught in a tidal surge and drift a little too close for comfort towards those gaping jaws.

The variety of fish that we saw was astonishing and included rarities never before seen such as a Yellow Margin Moray Eel, an enormous Star Pufferfish – very rare, and the highly venomous Lionfish.

Did You Know? Coral reefs are made from calcium carbonate secreted by corals. Most reefs are built from the polyps of stony corals that cluster in groups. Polyps are like tiny sea anemones but unlike sea anemones, they have exoskeletons which support and protect their bodies.

What will I see on the Reef Crest? The crest is the shallowest part of the reef and is subjected to the surge and the rise and fall of tides. When waves pass over shallow areas, they become agitated which is the precise condition under which corals flourish. Shallowness means there is plenty of light for photosynthesis by the symbiotic zooxanthellae, and agitated water promotes the ability of coral to feed on plankton.

Fish that you spot on the Reef Crest eat either the coral itself, small animals living near the coral, or seaweed and algae. The coral eaters include and abundance of parrotfish and butterflyfish and the Reef Crest is the best place to spot and photograph these wonderfully coloured fish.

The small animal-eaters include the fascinating cleaner fish which set-up cleaner stations and feed on the organisms that inhabit larger fish. Also roaming the crest are the sea-urchin-eating triggerfish.

Seaweed-eating fish include the damselfishes and groupers. Groupers cultivate the seaweed by removing creatures feeding on it such as sea urchins and removing inedible seaweeds.

        Blackside Hawkfish: (Paracirrhites forsteri) The Hawkfish is a carnivore that perches high upon corals to watch out for small prey such as shrimps or juvenile fish. The 20 cm Blackside Hawkfish has also been called Forster`s Hawkfish and the Freckled Hawkfish. One look at its face will tell you why. The same species has several colour forms ranging from yellow with smudged black to a reddish brown with black and is best identified by the dark spots on the head.

Weather and Ambiance : In the Maldives the north-east Monsoon runs from December to April and heralds the driest season although December itself can have up to 17 days on which rain falls - never for very long. The south-west Monsoon lasts from beginning of May till September. Towards the end you can get rain, high winds and thunder storms. October can have up to 19 days on which rain falls.

Being close to the Equator, Maldivian days and nights last an equal 12 hours. Every night at 6:00 PM the sun disappears spectacularly into the sea but the temperature only drops by a few degrees.

All year round the temperature is about 30°C and the temperature of the sea is between 27° and 29°C – ideal for snorkelling.

Did You Know? Fish are the oldest backboned animals having evolved nearly 500 million years ago.