As I live next to one of the best shore dive sites in northwest Scotland, it seems only fair to share it - safe in the knowledge that being at the end of a single track road 75 miles west of Inverness, I'm unlikely to suffer from serious diver congestion!

From the lay-by beside the ruins of Strome Castle (and our slightly less ruined house) there is a stunning view across Strome Narrows towards Plockton and the mountains of Skye beyond - if it's not raining. The view underwater is just as good, with something for everyone - scenery, critters, currents, sheltered corners for beginners. Shore and boat access are easy in almost all weathers. I've even dived under ice when the loch froze over - a good one for the logbook!

On each tide, strong currents pour through Strome Narrows - geologically, a shallow 'sill' where icebergs once fell off a glacier into the sea. This is the heart of Scotland's fjordland, and the narrows, only 10-20m deep, connect the ice-carved basins of Lochcarron (100m deep) with the Inner Sound (more than 200m deep).

A large tidal range (5m on spring tides) creates the strong tidal flows, bringing lots of food for marine animals. Within easy reach of the slipway there is a wide range of life typical of sea loch narrows - cliffs covered with sea loch anemones, bedrock slopes with kelp, featherstars and soft corals, cobbles and coarse sediments with horse mussel beds, brittlestar beds, maerl beds, flame shell reefs and lots more. We've seen more than 40 species of fish here so far, not including the porbeagle shark which made a routine dive memorable for a diver at a nearby fish farm a few years ago! Seals, porpoise and otters regularly fish in or pass through the narrows.

The tides dominate the diving at Strome. Slack water is around high and low water, and there is an enormous difference between the strength of the currents on springs and neaps. On springs, currents are strong and there is little slack, but catching it is essential if you want to do anything other than a drift dive. However, low-water slack on spring tides is conveniently at midday. On the neaps, there may be only a gentle flow, even at mid-tide, and plenty of slack. High-water slack is around midday on neap tides.

Underwater visibility is usually good, especially in winter when it is often more than 15m. In summer, there are short periods during plankton blooms when visibility drops to less than 6m. At any time of year a bout of heavy rain results in a layer of peaty freshwater moving down the loch towards Strome. But don't be too put off if it's the colour of whisky when you arrive - the fresh water floats on top of the denser sea water, and it's usually clearer (and warmer) below. Temperatures range from around 15ºC in summer to 7ºC in winter, a few degrees warmer than the east coast. This allows many southern species, such as the imperial anemone, to survive this far north.

The dives
Diving at Strome is dominated by the tides. With a boat to retrieve divers, you could drift this whole section of narrows at speed in one go, which is fun but you won't have time to stop and look for some of the smaller critters. Dives from the shore are best done around slack water, which is fortunately very predictable at low and high water. The aim is to start the dive at slack, and use the turning tide to take you where you want to go. The dives can be divided conveniently into three.

Dive 1: Round the island
I prefer to do this dive at low-water slack, so the incoming tide takes me round the island and into the slipway with minimum effort. It can also be done in reverse at high- water slack, but if you take this route there is more chance of a counter eddy to swim against at the end of the dive. Eilean an Fhraoich (Heather Island) is on the left (east) of Castle Bay, as you look out to Skye, and is only an island at high water.

Walk (carefully) from the lay-by down the steep bank between the castle and our garden wall, and snorkel out to the point on the left of the bay - a short distance at low tide. Submerge here and keep the rock face on your left throughout the dive. Ledges and crevices at the start are occupied by leopard-spotted gobies and bright spiny squat lobsters. Soon you will be on a dramatic cliff dropping to cobbles and gravel at 15-20m. This cliff is my favourite part of the dive - in fact, I regularly don't get any further! The vertical and overhanging rock at 10-16m is covered with thousands of white sea loch anemones (Protanthea simplex), sponges, sea squirts, Bloody Henry starfish in a range of garish colours, sea firs and sea slugs. Decorator crabs lurk among the undergrowth, disguised with whatever is in season. By contrast, less steep rock, and that near the base of the cliff, is heavily urchin-grazed and barren-looking, with some dense patches of red featherstars. It's certainly worth spending some time looking at different levels on this kelp-topped cliff.

Soon the rock curves to the east, and the steep, glaciated rock slopes are covered with soft corals (dead men's fingers) which thrive in the current, and are preyed on by giant triton sea slugs, up to 20cm long. Beneath small overhangs at the base of the cliff, look out for flourishing colonies of the sandy creeplet (a colonial trumpet anemone, not a fair-haired civil servant). Small holes are worth checking for Yarrell's blennies (Chirolophis ascanii), our paler and shyer northern equivalent of the tompot blenny, with similar tufts of head tentacles. Topknots, dragonets, sea scorpions and butterfish are often seen, and occasionally a lumpsucker or cuttlefish (Rossia macrosoma). But the most impressive animals are the common dahlia anemones - I've never seen bigger ones anywhere! These well-fed giants sit in a brightly coloured row at the base of the rock slope, waiting for windfalls of urchins or other animals bowled along in the current.

A steep sweep of gravel points to a short cut home if you are low on air; follow it up into the kelp and head northeast into a sandy bay, out of the current. Alternatively, continue following the rock around a small headland, which shortly leads north, up a short slope of gravel and boulders and into the same sandy bay in front of our house. As well as a good place to spend some time at less than 10m at the end of the dive, this is a good sheltered spot for a night dive (our house lights can be left on if requested before 10pm). Dozens of painted gobies will hunt in the wake of your fins, together with the occasional dragonet and dab, and there are numerous hermit crabs covered with a fluff of their own particular sea fir (Hydractinia echinata). Sea mouse, sand star, pipefish, grey gurnard, clingfish, long-legged decorator crabs and the diminutive goby (Lebetus scorpioides), less than 4cm long, are some of the more interesting critters here. It's now a short distance eastwards to the slipway, via some kelp-covered rocks where there has been a breeding population of rock cooks in recent summers, as well as the usual shoals of saithe and two-spotted gobies, and fifteen-spined sticklebacks in the shallows.

Dive 2: Brittlestar and horse mussel beds
At slack water, submerge from the slipway, and swim due south. After the fringing kelp, you reach a sea bed of dark pebbles and pale gravel at about 12m. As you continue south, the sea bed rises slightly, and among the bare black pebbles are patches of sea bed conspicuously covered with a variety of marine life - soft corals, brittlestars, sea firs, urchins and queen scallops, attached to clumps of horse mussels beneath. Further south, brittlestars in a wide range of colour varieties form dense beds. As well as common and black brittlestars, at Strome there are unusually large numbers of crevice brittlestars (Ophiopholis aculeata), with a distinctive scaly appearance and serpentine arms. Bright sunstars and big dahlia anemones generally have a brittlestar-free zone around them.

The marine life is patchy - head west towards the narrows and brittlestars become more dense; to the east there is more kelp on rock outcrops and boulders, and banks of clean, current-swept gravel. You can circle round east across maerl (see above), or west via the sandy bay in front of the house (as at the end of Dive 1) and back to the slipway, depending on the tide.

Dive 3: Maerl and flame shells
High-water slack is best for this dive - if the tide starts running during the dive it will bring you back to the slipway. From the slipway, head south for a short way on to the level sea bed, at 9-12m, then turn east. The sea bed changes to surreal purple-pink, as waves of maerl gravel become covered with a layer of brittle twiglets of live maerl (calcified seaweed).

Black brittlestars provide a nice contrast to the purple maerl, and clingfish, painted gobies and tiny, thumbnail-sized urchins live among the maerl branches.

Continue east, and the sea bed drops slightly to around 14m below the headland. If the rock face doesn't appear, head north to find it or the boulder fringe then follow them to the east. The first sign of flame shell reefs is a subtle change in the gravelly sea bed - it becomes covered with small white sea loch anemones. The flame shells industriously bind pebbles and shells together to make a nest in which they lie completely hidden. This stabilizes the sea bed, allowing all sorts of interesting marine life to attach - sea loch anemones, seaweeds, sea firs, sea slugs, prawns and decorator crabs. Carefully breaking open a nest will reveal the orange tentacles of a flame shell - be sure to handle it as little as possible, as its sticky tentacles are fragile and easily come off on a diving glove. Then, tuck it back in its nest - it will take the animal some time to repair the damage. The flame shell reef extends around the headland in a narrow band, with nests built up over rock and boulders in places.

East of the headland the nearshore sea bed is of broken bedrock and boulders, with a conger sometimes in residence in a deep hole underneath one of them. Offshore, brittlestars and queen scallops are common - there is a small local fishery (diving and trawling) for queenies here. When you've finished exploring, head back following the rocky coast to the slipway, via kelp and boulders, where there are lots of rock cooks in the shallows in late summer.

ESSENTIALS

Location
Strome is 65 miles west of Inverness, at 5º33.18'W, 57º21.53'N (Admiralty chart 2528). Follow the signs for Lochcarron, then Strome Castle, and park in the lay-by. It's an easy shore or boat dive; don't confuse North Strome with Stromeferry which is on the south side of the loch (with the famous 'Stromeferry - no ferry' sign).

Launching
Launch from the slipway at North Strome (tightish bend from the road). You can also launch a boat from Stromeferry and it's a short distance to North Strome. The hill at Stromeferry is a bit severe for towing, with steep inclines and hairpin bends. Keep the jetties and access clear of vehicles and diving gear - they are used by local fishermen.

Caution
Strome is generally quiet, but the jetties are working jetties so watch out for boats, including silent sailing boats coming through the narrows. Carry a delayed SMB in case you need to surface away from the shore. Anglers often fish from the point east of the jetty, above the flame shell reefs. There are often cages, creels and keep pots around the jetty and moored boats; leave them alone - they and their contents belong to local fishermen and shellfish farmers.

Medical
Surgery in Lochcarron, tel: 01520 722215. One of the GPs is a HSE-registered diving doctor. At the time of writing the nearest recompression chamber is in Kishorn, 16 miles from Strome.

Air and equipment
Bring everything.

Eating and sleeping
Rockvilla Hotel (Tel: 01520 722379). Good bar and restaurant meals, and the proprietor is a diver.

Strathcarron Hotel (Tel: 01520 722227). At the head of the loch, 8 miles from Strome. Good bar and restaurant meals.

Carron Restaurant (Tel: 01520 722488). At the head of the loch on the Kyle road, 9 miles from Strome. Good food.

B&Bs and self-catering: There are several good B&Bs on the west side of Lochcarron, and a few self-catering houses for small groups. Contact the local tourist office. Tel: 01520 722357, or check the Highlands tourist web site at http://www.host.co.uk.