I hadnt been so excited since I first dived the Hispania in the Sound of Mull. In front of me, sitting perfectly upright on the seabed, was the intact hull of a sunken fishing boat.

Brushing aside strands of mangled jellyfish, which hung suspended like spiders webs, I peered through my viewfinder. Tam, my buddy, was already disappearing into the distance, holding his large yellow video-housing firmly before him as if it were a miniature scooter pulling him through the water.

I finned after him, slowed by my camera strobes on long arms, and caught up at the wheelhouse, where he had wedged himself through the only open window. The wheelhouse was magnificent. The other windows around the top section were all glazed and intact; everything else was covered in a thick carpet of plumose anemones .

I found an open door at the back and carefully manoeuvred through it. I then had to take a deeper breath than normal, because the view was dreamlike. Everything was there, from the boats main controls and radar to the echo-sounder, net-monitoring alarm and various electrical aids. I had entered a 10-year-old time capsule.

Two seats faced towards the front windows, the material dangling off them and much of their outer surface covered in calcareous worm-cases, while bright red sea-squirts grew from what was left of the foam backs. These looked like parasitic beasts and the splash of colour made the scene resemble a black and white photograph touched-in with colour.

The windows were misted over with algae, and sea-urchins had grazed weird shapes onto them. In the middle of one, a fat plumose anemone, probably still digesting a feast of plankton and jellyfish, was fully retracted and looked rather grotesque.

My first trip to the Summer Isles had been 13 years before, when the mfv Fairweather V was still catching fish rather than attracting them. It sank in 30m of water on 4 February, 1991 close to the south shore of Annat Bay, near the entrance to Loch Broom.

The trawler was apparently driven hard onto the shore at Cairn Dhearg, for whatever reason. The water was thought to have rushed into an open hatch in the engine-room when a tugboat pulled her off the following day. Today this is one of the best-looking wrecks in the UK.

From the wheelhouse we made our way down to the shelter deck, passing a bathroom complete with toilet and sink, the galley with a cooker and eating area, and the skippers cabin, all as fascinating as the wheelhouse. We came out through a hatch onto the stern deck, next to the main winch from which ropes and netting seemed to disappear in all directions.

On the seabed we checked out the variable-pitch propeller before returning once more to the bow via the engine-room and shelter-deck, with time for a last look at that wheelhouse.

The Summer Isles are home to seals, otters and seabirds, with Tanera Mhor, the largest island, the only one permanently inhabited. You can walk to the closest island from the mainland on a low tide. Only one regular dive vessel operates here, the mv Goldseeker. Its friendly owners Scott and Robyn always had tea or coffee waiting for us as we emerged from the cold water.

We would meet at 9 oclock each morning after a short walk downhill from our hotel to the main harbour pier in Ullapool, and were never more than an hour from our chosen dive-site.

There are three other excellent wreck sites. The photogenic Boston Stirling steel trawler, sunk in 1983, lies on its side in just 6-15m on a sandy bottom off the south-east side of Tanera Mhor. The Margo is a prawn trawler which sank two years ago in the approaches to Lochinver and lies on its port side in 30m. And the Innisjura coastal trader sank in 1920 in 35m and lies very close to the Fairweather V.

But one of the best dive sites in the Summer Isles, and arguably in the north-west of Scotland, is Conservation, or Cathedral, Cave which, when I first dived it in 1988, I logged as Sion Ghais Cave. Although a shallow dive, its particularly spectacular, with a dome-shaped roof and walls covered in anemones, sponges, dead mens fingers, sea-squirts and hydroids. The jewel anemones are brilliant, as are the various nudibranchs that can be spotted feeding on the hydroids and sponges.

Beware of swell and strong currents, or you will find yourself being swept away from the cave onto a kelpy boulder slope and then onto a seabed covered in brittlestars.

Conservation Cave was one of my best early dives, and my first deep dives were also made around these islands, at a spot called Sgeir Dubh, or Black Rock. This is the largest skerry or rock found between Tanera Beag and Glas-leac Mhor, and is known for its masses of cod and pollack.

I was diving with a member of our club notorious for diving deep. I remember him cursing because he had been given an SMB with only 30m of line. There he was, one arm up as he tried desperately to get deeper down the sandy slope. We were supposed to be going to a maximum of 25m, as I was still a novice.

Another dive that stands out is Stac Mhic Alonghais near Conservation Cave, a good scenic dive, and the first place I ever saw squid. On a recent trip I also enjoyed Lattos Rock, a skerry near Tanera Mhor. This fascinating site consists of a flat-topped pinnacle covered in thick kelp in 6m, a series of mini-walls, ledges and then a steep sandy/muddy slope.
The kelp provided shelter for many species, from spider-crabs and scorpionfish to gobies and blennies and, for the observant diver, nudibranchs and sepiolids, while the ledges and overhangs offered shelter to squat lobsters and lobsters, and the sand/mud was home to sea-pens, scallops and swimming crabs, so there was something for everyone. Which sums up the Summer Isles.

As a postscript, a company is currently considering applying for a licence to run a cod and possibly salmon farm near the Fairweather V, a move which is causing some concern as it could threaten diving tourism in the Summer Isles. The local sub-aqua club is currently organising a petition to forestall such a development.

The remarkably intact wheelhouse on the Fairweather V fishing boat wreck
preparing to dive around the Summer Isles
diver on the Boston Stirling wreck
sitting up and taking notice, a tompot blenny


GETTING THERE: The Summer Isles are off Scotlands north-west coast. To dive them, most people base themselves in Ullapool, an hours scenic drive from Inverness.
DIVING: mv Goldseeker operates from Ullapool, 01854 655 272 e-mail: Goldseeker@btinternet.com.
ACCOMMODATION: Gavin Anderson stayed at the Riverside Hotel, which he says does a great breakfast and has family rooms, 01854 612239. Other options at similar rates are Eilean Donan (01854 612524), Old Surgery Guest House (01854 612520), Dromnan Guest House (01524 612333) and Sheiling (01854 612947).
WHEN TO GO: Summer.
WATER TEMPERATURE: 6-16°C - take a drysuit.
FOR NON DIVERS: Walking, swimming, pony-trekking, angling and golf. The award-winning Museum & Visitors Centre offers a history of local crofting and has aquariums with local marine life. Visit the Highland Stoneware Pottery or Leckmeim Gardens with its 19th century arboretum. Twenty-five miles north of Ullapool is Achilitbuie, with its famous hydroponicum (water cultivation) and smokehouse.
FURTHER INFORMATION: Achilitbuie and Summer Isles Tourist Association, 01854 612135, www.coigach.com