Diver by Jean-Michel Langlois, who was the overall winner of the H2O photo competition

THE SCORPIONFISH FAMILY IS BIG. Some 400 diverse species can claim membership, and quite a few of them seem to live on the tiny wreck called Tug II off leeward western Mauritius.
I hadnt realised how wide-ranging this family was, and how outlandish some of the distant rellies. If they moved in next door, youd apply for an ASBO on appearances alone.
I picked my way between the often unprepossessing inhabitants of this 30m open wreck, purpose-sunk 25 years ago and one of many small artificial reefs off Mauritius.
Every creature seemed to be armed to the spines with toxins and stingers, and to be as self-possessed as such protection would entitle them to be.
For a start, the wreck was crammed with lionfish of all sizes, and lionfish are of course a type of scorpionfish. Their sharp spines can inject a cobra-like venom to leave the unwary swollen, paralysed and pained. They do this only if you bother them, but the Tug II lions have a habit of sneaking up behind you if you stop in one place too long.
With their fierce Samurai looks, lionfish are always good to watch, and to watch out for.
The sort of big, heavily camouflaged scorpionfish we normally think of, similarly equipped with venomous spines on dorsal, ventral and anal fins, lurked inside the open hull. I didnt see any stonefish but thats the trouble with stonefish - you dont always see them. What I did see was what I had been advised to look out for - two small but fascinating members of the Rhinopias branch of the family, a weedy scorpion-fish and Eschmeyers scorpionfish.
The weedy variety, as its name suggests, has incised fin membranes that make it look like a tatty piece of seaweed. I didnt even spot it on my first visit to the wreck, but on the second it was wobbling slowly along the bare white sand at the stern, salmon-pink and blotchy, so fairly obvious.
Its relative, the pride of American icthyologist William Eschmeyer, lay just metres away, on the stern. Its prominent fins are more like fins as we know them. But its still a bizarre-looking creature, barely distinguishable from the algae that covers the wreck until you illuminate it, when it turns bright orange - or yellow, or pink.
Everyone seemed very excited about these Rhinopias, so I gathered that they were quite rare.
I would see many other peculiar scorpionfish on other dives - of the leaf and devil varieties, as well as those familiar masters of disguise, the humpbacks. These scorpionfish are usually immobile, but when they do decide to make a strike, usually at prey, their acceleration from zero would make Jeremy Clarkson goggle.
Under Tug IIs stern big tomato groupers and soldierfish rested among clouds of anthias. It was a little photographers paradise, with strobes flashing like lighters at a Coldplay concert.
It was a similar story at Serpent, another favourite Mauritius site in the Flic en Flac area. This was not the concentrated metropolitan life of Tug II but the suburbs, a string of volcanic boulders topped with soft coral straggling through the sand at around 25-28m.
It was well-populated, however, and again with malevolent-looking creatures - lionfish, scorpionfish and stonefish and an impressive array of gurning moray eels, speckled, blue, green, black, you name it.
When I noticed a large, vivid blue porcupinefish poking its head out from an overhang and looking up at me with big Bambi eyes, it seemed like an innocent abroad among all these hard cases. I started wondering if even this innocence was all it seemed.
One large leaf-fish showed up shocking pink even at this depth - no attempt at camouflage here. But leaf-fish are the wimps of the scorpionfish family - they dont fight back if attacked, they just fall over.
There was a lot of grooming going on, cleaner shrimps hard at work on their clients all over the reef. And the scuba paparazzi were busy too, as they had been on my first dive in Mauritius - only on that day it had been business.
We had been on the promisingly named Aquarium, on which underwater photographers from all over Mauritius and Reunion were competing in the national H2O digital contest, which I was there to help judge.
The site, made up of rock with sparse soft coral and sponge coverings, had looked unpromising to the mere observer, so I was pleased later to see the colourful diversity of life that the competitors had captured.

A VIVID MEMORY WAS OF the large snub-nosed rudderfish or drummers that started mobbing me in open water above the reef. I had no wallet or mobile phone to hand over, and at first assumed that someone had been breaking the rules and feeding them.
But it seemed that they were simply used to divers, and in the absence of food would peck away happily at dead skin or anything else about you that took their fancy.
Rudderfish have big bodies and small mouths. Their name comes from their habit of following boats for scraps - these are voracious creatures and clearly saw me as a meal ticket.
I left the rudderfish to the photo competitors, who had no shortage of other subjects - the various scorpaenidae, bannerfish, butterflyfish, strings of snappers and a small whitetip shark that was happy to pose with a troop of soldierfish.
Sharks and rays are becoming rarer, particularly in western Mauritius, although they are said to be more numerous in the north and particularly on the tougher-to-dive east coast. Shortly after my visit, the Sun Diver centre with which I was diving started conducting bull-shark dives further south, which would certainly inject some excitement if you fail to find scorpionfish endlessly fascinating.
Sadly the Mauritian government, for all its talk of marine parks (it has one in the south) is still doling out licences to the Japanese long-liners whose mission it is to make the shark history.
Mauritius is caught in a dilemma. With severe pressure on the sugar industry that has always sustained it, it needs to raise the yield from its other cash cow, the 750,000 well-heeled visitors who come here every year, drawn by the islands romantic associations, fine-sand beaches and reputation for luxury.
A million tourists a year might do the trick - but crank up the numbers too much and that hard-won reputation as the destination of choice for romance-seekers might start to lose its allure.
So the trick must be to squeeze more out of the existing tourist population - and to top up with income from such sources as Japanese fishing interests.
If I have gone on at some length about scorpionfish and other such reef- dwellers, its because these seemed to be the keynote attraction where I dived in Mauritius. I would say that the dives were most fun for photographers.
Meanwhile, if the Sugar Beach Resort typifies the quality of accommodation, its easy to see why Mauritius is such a popular holiday destination. A sprawling resort based around a French colonial mansion, it offers comfortable accommodation and excellent food, with imaginative buffets every night.
The accommodation is set out in small apartment blocks, but wander north and you enter the grounds of sister-resort La Pirogue, which is an elegant take on a fishing village of thatched huts.
Sun Diver is located here. Very good it is too, with its two open boats and friendly, knowledgeable staff under the capuccino-fuelled direction of the centres founder, Thierry De Chazal.
This western part of the island also boasts some splendid topographical features carved out of the ancient volcano that is Mauritius.
A fine example is the Cathedral (yes, you knew there had to be one). Enter this monumental rock structure through a gaping fish-filled archway above a seabed at about 30m, and turn back to enjoy the view into the blue.
Inside the Cathedral youll find small caverns with diver-created air pockets above, and fish of all sorts hanging at odd angles in the water.
Fine-tune your focus and youll spot mantis shrimp and maybe tiny hawkfish before you exit up a wide chimney to the top of the reef.
Here squat false stonefish stand guard like white gargoyles. Terrific, I might have guessed - more scorpionfish.

a blenny peers from the coral
weedy scorpionfish
Eschmeyers scorpionfish
on the Sun Diver boat, with director Thierry de Chazal centre
Dont-mess-with-me scorpionfish
innocent-looking porcupinefish
whitetip reef shark and soldierfish
tomato grouper


GETTING THERE: Fly from the UK with Air Mauritius.
DIVING & ACCOMMODATION: Sun Diver (00230 453 8441, email sundiver@intnet.mu) is located at La Pirogue next to the luxurious Sugar Beach Resort (00230 453 9090, www.sugarbeachresort.com)
WHEN TO GO: Diving is year-round but the western and northern coasts are warmer and offer calmer seas. Water temperatures are around 27°C. It is windiest in February, March, September and October.
MONEY: Mauritian rupee, credit cards.
PRICES: A standard room with half-board at the Sugar Beach Resort costs from £200 a night for two adults in low season (April-September). Return flights start at around £460, and a 10-dive package with Sun Diver costs around £125.
TOURIST INFORMATION: 020 7584 3666, www.mauritius.net