Loading up the RIB in Sardinia.

CORSICA/SARDINIA:
Lavezzi
Big granite scenery standing in the current between Corsica and Sardinia should be enough to make a pretty good dive, but the Lavezzi Islands have that bit extra to turn 'pretty good' into 'superb'.
Within the boundaries of the Parco Nazionale Arcipelago La Maddalena marine reserve, Mediterranean groupers have had the chance to grow to full adult size. Until you have seen one, you won't appreciate just how big that is.
To support such a population, stocks of other fish are also doing well, as witness big shoals of familiar Mediterranean species such as bream, salpe and sardines. The groupers also get the occasional handout from divers, though considering their overall size and numbers, this can't be more than a snack.
But with these treats and plentiful divers, the groupers are sometimes friendly and in all cases tolerant of a cautious approach. Be careful not to spook them and they will just rest there, looking you in the eye.
They're letting you know that this is their spot and that they're not planning to leave it just for some bubbling intruder.
* Location Sardinia, www.locationsardinia.com



The harbour at Zulyana, in Croatia.

Anti-aircraft gun on the wreck of the S57.
CROATIA:
S57
A German torpedo boat from World War Two, the S57 was made from steel frames covered in plywood.
After more than 60 years under water, the plywood is long gone and the frames and engines are encrusted in bright orange and purple sponges, fed by the gentle current running through the open skeleton.
The S57 met its end while escorting a supply convoy to Dubrovnik. Allied torpedo boats attacked as the convoy passed Korcula, sinking all but the S57 and one tanker.
The badly damaged S57 made for the shore near Zulyana on the mainland and was scuttled in an inaccessible bay as the crew escaped up the cliffs. Only the tanker made it to Dubrovnik.
The wreck lies bow to the shore, the bow in 20m and the twin propellers in 35m beneath a square stern.
As you descend the slope you see first the bow torpedo tubes, faired in on either side of the bow and complete with the compressed-air plumbing of the launch mechanism and live torpedoes.
Behind these, another pair of torpedoes are stored on deck, ready for reloading. The tiny winches and cables of the reload mechanism join the torpedoes to the doors at the back of the tubes. On the aft deck, a twin anti-aircraft gun still swings on its mount.
It's a small wreck and can feel crowded with a boatload of divers. Try giving the others a 20- or 30-minute head start. They will all be out of bottom time and starting to leave as you arrive.
* MM-Sub, www.mm-sub.hr



Diver on the Zenobia in Cyprus.
CYPRUS:
Zenobia
While some of our selection of world-class Mediterranean dives are a matter of personal choice, it would be inconceivable to consider any alternative to the Zenobia off Larnaca in Cyprus. The 12,000 ton ferry sank following a ballast management computer error in 1980.
There are divers who go on a two-week holiday to dive nothing but the Zenobia, then return a year later to do the same again.
There are dive centres that dive nothing but the Zenobia. They may have other dives on their books, but the Zenobia is all their customers want.
It would even be possible for a diver, having passed basic Open Water on top of the Zenobia, to gain all subsequent qualifications through to normoxic trimix, rebreather and advanced wreck penetration on this one wreck (let us know if this is you!).
After exploring the outside of the wreck, the opportunities for penetration cross the whole spectrum of severity, from swimming the length of the vehicle deck, to the cabins of the superstructure and down to the engine-room.
Perhaps this is the Zenobia's devil of temptation. More than one diver has ventured further inside than they were equipped or trained for, and more than one of these has failed to return to tell the tale.
* Octopus Diving, www.octopus-diving.com



A common octopus in the Straits of Gibraltar.
GIBRALTAR/SPAIN:
Los Bolos
They call it Los Bolos because you need the balls to dive there. With a constant current into the Mediterranean, perhaps moderating to 1 knot on a favourable day with a favourable tide at 'slack' water, the current here in the Straits of Gibraltar is never slack enough for beginners. You need both bolos and experience.
Eons of continuous current have etched their way into the rock. The slightest softer seam widened into cracks, the cracks into crevasses and the crevasses into towering canyons. All are pretty much in line with the current, though winding slightly as harder regions of rock resist the scouring.
Walls are undercut where they meet the seabed. Cracks big enough for divers to enter run along the base of the walls, the small pebbles, gravel and sand of the seabed dancing in the current and accelerating the erosion.
In some places cracks from parallel canyons have met and widened to form swim-throughs and arches, all a transient stage in the erosion of rock to gravel.
In other places the undercuts are deep enough for huge blocks to split from the walls of a canyon, opening a crevasse and a new route for the current to exploit. It's a wonder that any marine life can hold on. But it does, and lots of it, ranging from tiny orange cup corals to purple and yellow gorgonians. Colourful life covers the walls of the canyons.
It's a dive that is a challenge, a thrill and spectacular all rolled into one.
* Happy Divers, www.happy-divers-gibraltar.com




The entry and exit point for the Coral cave dive on Gozo is the Blue Hole, immediately in front of the arch of the Azure Window. The actual cave is round the rocks to the west - off the left-hand side of the picture.

Fine corals and bryozoans decorate the walls and roof of the cave.
GOZO:
Coral Cave
Just around the corner from the classic archway of the Azure Window, Coral Cave was discovered only in the 1980s. How could such a big cave be missed?
The cave is half a stretched funnel, the opening being an archway rising from past 30m to as shallow as 10m and more than that wide, leading back perhaps twice that far beneath the beach.
Eroded by the surge of waves trapped and funnelled into the cave entrance, one day the back of the cave will push far enough to break through to the beach above and create another blue hole. Or the entire roof will collapse - or tunnel all the way through to the Inland Sea.
On the way into the cave, follow close to one of the walls or roof, admiring the delicate lace of corals and bryozoans but being careful not to break them.
At the back, look out for groupers hiding in the deep shadows. Then turn and admire the view through the enormous arched entrance into the deep Mediterranean blue.
But don't spend too long. The usual exit point is 15 minutes' swim back to the Blue Hole or, if that is too rough, 15 minutes further through the Azure Window and round the corner to the Inland Sea.
* Calypso Divers, www.calypsodivers.com


Wall of red gorgonians at Bledes na Bosc in Ibiza.
IBIZA:
Bledes na Bosc
In UK waters and on tropical reefs, the usual colour of the local species of gorgonian is a biscuity brown, some might even say pink. In the Med, the usual species of gorgonian is blood-red, purple at depth because of blue filtering of the light, sometimes yellow, and when the water gets too warm towards the end of the summer, sometimes bleached white.
But throwing the exceptions aside, red is the colour that predominates, nowhere more so than the wall at Bledes na Bosc in the Cala d'Hort Marine Nature Reserve off Ibiza's north-west corner.
The wall faces north-west, so dive it in the morning and it will be in the shade. That's nice for a photographer, allowing flash to bring out the colours of the gorgonians with perhaps a sunburst in the top corner of the frame. Dive it in the afternoon and the sun lights up the forest from the shallows to past 50m, where it ends in a sandy slope.
Either way, chances are there will be a current, probably from the west, driven by the general circulation of the western Mediterranean basin, though sometimes from the north-east when winds and tide combine to overcome the general flow.
After drifting and admiring the forest, ascend the stepped wall and look into the cracks for a lurking moray or conger eel.
* Seahorse Diving Centre, www.seahorsedivingibiza.com


The Um El Faroud wreck in Malta.
MALTA:
Um-El-Faroud
The Libyan tanker Um-El-Faroud wasn't intended to be an artificial reef, but once it had been fire-damaged beyond repair, cleaning and sinking it for divers was the best option.
It's the sort of artificial reef project for which Malta is building such an excellent reputation. It's close enough to an easy shore entry that it can be reached by following the reef out, or by a long surface swim. It's shallow enough to be accessible to all but basic Open Water divers, and deep enough not to be broken by winter storms.
The Um-El-Faroud is about 15 minutes into the dive out from the inlet at Wied iz-Zurrieq. Allowing the same time to return, the slow ascent on the reef makes for a safe profile with a chance to bubble off a few minutes' decompression without really noticing it.
They even sank the ship the best way round, with stern and superstructure closest to the shore.
There are multiple decks and companionways to explore, and inside are all the cabins and the gallery leading to the engine-room.
It's a long dive just to cover the stern and make it back along the reef. For those frugal enough with a 15 litre cylinder, or crafty enough to have packed a twinning kit to bind a pair of 12s together, the bow is within reach after the usual pipework of a tanker's deck.
* Maltaqua, www.maltaqua.com


Entering the cave at Pont d'en Gil in Minorca.
MINORCA:
Pont d'en Gil Cave
Among the Mediterranean's diving attractions are the caves that permeate the waterline and just below. With limestone being slightly soluble, the slightest crack in the rock is both dissolved by the water and hammered open by the waves to produce caves ranging from letterboxes to caverns big enough to drive a double-decker bus through.
Among thousands of caves, Pont d'en Gil stands out because it is a seawater cave adorned with the classic stalactites and stalagmites that can form only when fresh water drips from the ceiling of an otherwise dry limestone cave.
Each drip leaves minuscule traces of previously dissolved limestone on the ceiling, then another minuscule amount as it strikes the floor.
Over thousands of years, the deposited rock builds up, first to tiny straws, then larger and larger wedges.
Pont d'en Gil was in the right place at the right time. When sea levels were lower during the last Ice Age the cave was decorated by fresh water running through the limestone to the sea.
The ice age over, sea levels rose again and salt water took over. The submerged cave formations were frozen in time.
* Bluewater Scuba, www.bluewaterscuba.co.uk


Salpe, a familiar site everywhere.
SPAIN:
Dolphin Cave, Medas Isles
Way back in 1983, someone in Spain had the bright idea of declaring the Medas Isles off L'Estartit a marine reserve. The islands were already popular with divers, and since gaining their protected status the quality of marine life has grown ever stronger.
A signature dive is Dolphin Cave, named after a statue at the southern entrance. Calling it a cave is a bit of a misnomer, as it is actually a tunnel running 50m through a corner of the island, and not just a skinny tunnel. It's big enough to drive a bus through.
The dive site is the cave, but the enjoyment has as much to do with the reef outside, with its shoals of bream and salpe, flittering clods of anthias, persistent swarms of wrasse, and some sizeable groupers - all benefiting from the protection of the marine reserve.
The reef provides plenty of colour, red gorgonians complementing yellow cup corals. Look closely to spot nudibranchs and scorpionfish or, in the cracks, moray and conger eels. They have even been known to share cracks together here.
* La Sirena, www.la-sirena.net


A RIB leaves the harbour.
TURKEY:
Duchess of York, Kalkan
At one point it was thought to be just one wreck, the Duchess of York, broken in two or three pieces, with the aft part shallow on the rocks and the bow tumbled to 60m below. But the parts did not add up, and once diving from Kalkan opened up, it turned out that the Duchess of York was just the shallower wreckage, and deeper dives soon revealed that other more extensive wreckage was an altogether different wreck.
The steamship Duchess of York was built in 1893 and struck the rocks of Kalkan in 1916 while carrying supplies to Gallipoli.
The second, deeper wreck is still not conclusively identified, though currently thought be the Sakarya, a Turkish ship that went missing with a cargo of coal and chromium ore in 1957.
* Dolphin Scuba, www.dolphinscubateam. com