On a calm day in 1809, three fisherman drowned in Loch Ewe when their small boat was attacked and sunk by a whale. These waters are among the best in Europe for cetaceans (whales, dolphins and porpoises). The Gulf Stream brings warm, plankton-rich water and the swirling currents around the islands bring nutrients to the surface. The plankton flourish; the fish eat the plankton; the whales and dolphins eat the fish.

Porpoise or dolphin?

The strongest currents are at headlands and narrow sea passages, so these are good places to look for marine wildlife. Calm days are best, and early morning best of all when looking west, as the low sunlight shines off their wet backs. On most summer days, either the harbour porpoise or common dolphin – or possibly both – can be seen, given a little patience, in Loch Gairloch. But which is which? At 6ft (2m) or less, the porpoise is smaller. It has a short, stubby fin compared with the dolphin's more elegant one. Harbour porpoises are normally shy, but the ones at Gairloch are untypically friendly, often approaching boats. Endangered in the world as a whole, the ones at Gairloch are doing well.

What the future holds

The whaling industry in Scotland ended in 1951, but serious threats remain. Dolphins and porpoises are accidentally caught in fishing nets, and floating plastic rope and old nets are another danger. Pollution from agriculture and forestry releases heavy metals and pesticides into the ocean. Fish farming is also probably damaging the dolphins. More fish sewage than human sewage goes into the Hebridean seas, all of it untreated, and anti-fouling paint on fish farms contributes more chemicals.

Cetaceans use sound signals for finding fish, as well as for communication. Interference comes from ships, dredging nets, seismic oil exploration and underwater beepers fitted to fish farms to keep seals away.

We don't know how well the dolphins and porpoises are doing. The growth of the whale-spotting industry means that we are just starting to discover how the populations are growing or declining. Marine tourism in Scotland today is a booming trade, supporting several hundred jobs. By going on one of these trips, you'll contribute to crucial research. A responsible boatman will not pursue the animals or steer into the middle of a group, but move quietly and wait for the dolphins to approach the boat.

Cross the road and head up to the right of the newer cemetery. Turn left at its corner, going into trees to a path above. Turn right until a footbridge leads on to a wide path that soon runs downhill. The main path bends right (greentop waymarker) and runs down to a tarred driveway.

Turn left along a tarred track to pass Flowerdale House. The track passes to the left of a lovely old barn and turns right at a sign for Gairloch Trekking Centre. 

At the trekking centre keep ahead on a smooth track. Where it bends uphill, keep ahead on a wide path, still to the left of the stream, to reach a footbridge built by the Royal Engineers, just before you get to Flowerdale Waterfall.

The path leads up past the waterfall to cross a footbridge above. It runs up into a windblown pine clump, then turns back down the valley. After another footbridge you pass a memorial to the blind piper of Gairloch, just before you reach a forest road. Turn left, away from the river valley, through felled forest that's regenerating naturally (with birch, alder, pine, willow and rowan).

After 0.5 miles (800m) gently uphill, a footbridge on the right is the start of a path back towards the river. It leads through scrub birch and bracken. The path bends right at an old fence cornerpost and goes down through bracken and birch to reach the valley floor at the corner of a walled paddock. Turn left on a grass track beside the wall, and cross a small stream to join a firm stony track.

Turn left for a few steps, until a small bracken path runs up to the right past a power pole with a faint blue paint mark. At the hilltop the path bends left under oaks, then left again as it drops to rejoin the firm track. This soon meets a larger track, which is the old road from Loch Maree to Gairloch. Turn right along this, through a couple of gates, to reach the Old Inn at Charlestown.

Cross the old bridge, and the main road, towards the pier. Turn right at the signpost for the beach, to a stepped path to the left of Gairloch Wildlife Gallery hut. The tarred path, signed for the beach, turns left above the pier, then turns right into the trees. It bends left again and emerges to run along the spine of a small headland. Just before being carried out to sea it turns sharp right at a signpost, and crosses above a rocky bay to the fort (An Dun). A gravel path runs along the back of the beach, then turns right to the car park.