It was a bright afternoon, the last party of French divers had departed and their replacements had yet to arrive. So instead of having to find space on a packed hardboat, this time it was just me, the skipper and dive guide Sami Ouchtati, whose father says he bought the dive centre Loisirs De Tabarka because his son was into diving.
We headed for Tunnels Reef, one of many sites within 15 minutes of Tabarka Harbour, around the point on which an imposing Genoese fort broods.
Today visibility was exceptional and for once this extended to the tunnels themselves, 20-25m down. Usually the water within them would be dark, milky and cool, but today sunlight was bursting through the gaps in the ceilings in bright columns and illuminating the walls and floors.
I had dived these tunnels a number of times before, but until now had failed to appreciate just how varied they were. Its like some bizarre cavern design show - one exhibit has such sharp planes it appears to be chiselled out, others are punctuated by columns and pinnacles, while the walls of the next resemble tumbling rolls of fat. Some are as big as cloisters; in others you would be hard pushed to get two divers abreast.
Today the water in the tunnels was almost as warm as it was outside - it can feel chilly, though with the overall water temperature in the mid-to-high 20s I usually opted to wear a shortie. Even on deeper dives here hypothermia seemed only a remote possibility.
One such deeper dive came the next morning at nearby Cap Galina, otherwise known as Black Coral Caves. Down at about 40m our guide led us to some slightly forelorn black coral trees. He insisted on showing us how hard it was to break their horny structures - just as well, in view of the vigour of his demonstration.
Black coral is not a common sight - much of it ends up as jewellery, like the red coral you see in souvenir shops in Tunisia, and of which too little remains in these comparatively shallow waters.
Only the inner skeleton of the black coral is in fact black - the living tissue on those we saw was white but it comes in a variety of bright colours.
Though few fish were around on this dive, that was untypical of Coral Coast diving. For the Med these are well-stocked waters. On a relaxing dive that afternoon at Cap Tabarka, for instance, we stayed at no more than 13m and ranged over brightly lit and dramatic terrain packed with colourful life.
Starting where the massive cliffs plunge sheer into the sea, we explored areas of giant boulders, crevices and canyons, squeezed into one tight tunnel, and then made our way along lofty walls covered with dahlia anemones, sponges and gorgonians.
From time to time we would be engulfed by shoals of chromis, damselfish and tiny neons, and examined by the various types of bream - cow, two-banded, African white and bogues - which find that life suits them here. One of our guides showed off his party trick, mesmerising Turkish wrasse with two pointing fingers, a la Crocodile Dundee.
Elsewhere you find grouper. On one visit to local diver-magnet Grouper Rock, a massive pinnacle which rises from about 30m, our guide Tarek touched down surrounded by swirling green clouds. It was interesting to observe how his copious nosebleed excited the fish, which came tumbling in to find out what was going on - the grouper, always inquisitive anyway, bream, combers and damselfish.
Once locked on, the groupers hate to leave you unescorted as you explore their home turf. They look as if they think you want to pinch something. Of course, what they want is food - theyve been protected and pampered here for many years, growing plump as a result.
Size matters. On several occasions at Grouper Rock we stopped to peer at the celebrated giant octopus that occupies a crevice overlooking a large part of the reef - its hard to tell just how big this creature is, because all that can usually be seen are sections of tentacle the width of your average thigh, and a baleful eye. Its hard to imagine how it gets in and out of its hole, but Jules Verne himself would have been impressed.
And at a site called the Canyons we came across what appeared to be the lip and handle of an amphora. Although these are not commonly found on the popular sites, a local historian told me that several ancient shipwrecks lie in accessible waters around Tabarka, which was originally a Roman settlement.
I had dived here before, two years ago, on an exploratory trip into what is still very much a French diving preserve (Tabarka Road, December 1997). While I had enjoyed the diving I had been unimpressed by the dive centre, one of the handful in Tabarka, and also dubious about whether British divers could be bothered with the 100-mile transfer from Tunis, much of it over corrugated roads. British tourists usually head for the east coast, where diving is limited.
As it turned out, the Tunisian tourist authorities were sympathetic. They built an airport at Tabarka, and once a week during 1999 Monarch would drop off a small band of tourists from Gatwick - including me - while the other passengers continued south-east.
Sadly, that band was just too small. The bad news is that UK flights will be directed to Tunis again next year, the only consolation being that they say the road link has been improved.
I reckoned there was enough of interest in Tabarka to keep the average diver happy for a week or so, and that for those who enjoy something a bit different it would provide a good Mediterranean family/diving holiday. The Tunisians are friendly, the beaches soft, sandy and uncrowded, a wide variety of sports and watersports are freely available and the food is good.
It is inexpensive, there are stunning Roman remains at Bulla Regia and Dougga and there was even an international jazz festival going on.
So I took my wife and teenage sons along to the hotel at which I had stayed before, complete with Olympic-sized pool and relentless but good-humoured activities regime. The family assure me that they enjoyed their fortnight - even in the absence of significant shopping opportunities - while I slipped off for regular forays under water.
The tourist people say that since my previous visit they have made efforts to study how Red Sea dive centres do what they do. Certainly I have no complaints about Mr Ouchtatis dive centre - quite the opposite. Called Loisirs de Tabarka, it is located in the harbour, handy for its hardboats Barbaros and Sea Queen.
The centre is well equipped, has neat premises and friendly local staff. They speak enough English between them to provide a good briefing even if, as I was, you are alone among a crowd of French-speakers.
On my earlier trip, windy weather had prevented us visiting the island of La Galite, 35 miles north-east of Tabarka, and I was determined to do so this time. Loisirs de Tabarka does the three-hour run most Sundays, for divers and non-divers alike. The only people on La Galite are customs officers, there to intercept illegal African immigrants heading for Europe. They share this craggy nature reserve with a colony of walruses, a rare sight this far north.
As the barbecue was being lit on board, Sami and I dropped over the side to examine the wreck I wanted to see, a Tunisian freighter that had come to grief in a storm 40 years before.
There it was - nothing. The sea was calm, visibility awesome, and I had wrongly assumed that the skipper had put us right over the wreck, but we hung in mid-water at around 20m, circling and scanning the bare seabed below.
Sami concentrated on his compass and seemed to be in denial. I had long given up hope of finding our goal when the imposing stern materialised. As we seemed to have done little but rotate for the past 20 minutes, the wreck gave the peculiar impression of having found us.
Nobody seems to know the name of the ship, but it is impressive, more than 60m long, lying bolt upright and intact, heavily encrusted. We swept over the decks, examined the superstructure, from where the odd moray eel and scorpionfish glowered at us, and dropped into the gloomy forward holds, but there was too little time to root around in any detail.
Frustratingly, neither was there time - or indeed air - for a second dive after lunch. It was the one occasion on which a faster boat would have been useful.
Sami, I was surprised to learn, had not dived the wreck before. But then, I had the distinct impression that neither the dive centre nor its mainly Continental visitors was that interested in old boats - its the groupers, corals and tunnels that capture the imagination. Theyre all there waiting, just around the point.


GETTING THERE: Gatwick to Tunis with GB Airways, two-hour transfer by road to Tabarka.
DIVING: Loisirs de Tabarka offers 10-dive packages for£120 (2168 670 664) or book through Aquatours, which offers diving packages (020 8398 0505, website: www.aquatours.com).
WHEN TO GO: Open all year round, but uncertain weather makes June-September the safest time to go. Temperatures rise to 40C in summer, when it is dry, but it is rainy at other times and although winters are mild it can even snow in this mountainous area.
ACCOMMODATION: The big tourist hotels lie along the beach east of Tabarka, a walk or taxi-ride from the dive centre, but taxis are cheap. Two weeks at the comfortable Abou Nawas Montazah, with half-board accommodation, flights and transfers, costs between£449-649 per head during summer. Call Aquatours or Panorama Holidays, which can book other accommodation in the town. (01273 427000, www.phg.co.uk).
MONEY:Dinars. Take travellers cheques; credit cards arouse suspicion and can take forever to process here - even in banks!
FURTHER INFORMATION: Tunisian National Tourist Office 0171 224 5561(www.omtt.com).
Start a Forum discussion on this topic