Chesil Beach Dorset

Weymouth · Dorset · United Kingdom

Chesil Beach is one of the great geological features of the English coast: a shingle barrier stretching 29 kilometres along the Dorset shore, part of the UNESCO Jurassic Coast World Heritage Site. For most visitors, it is a landscape feature viewed from the cliff paths above. For divers willing to navigate the challenging pebble entry, it reveals a surprisingly rich temperate marine world that rivals any shore dive in British waters. The entry is the test. Chesil's pebbles are large and round, shifting underfoot with every step, and the gradient drops steeply into the water. In full kit, the 50-metre walk from the car park feels like a mountaineering approach. But once you are through the surf zone and swimming out over the initial sandy seabed, the terrain changes to low rocky reef and the diving begins. I visit Chesil primarily for the cuttlefish. Each spring, from late April through June, hundreds of common cuttlefish converge on the shallow reef for mating. The males put on theatrical displays: pulsing with chromatic waves, extending tentacles in threat postures, and physically grappling with rivals. The females, usually attended by multiple suitors, eventually deposit grape-like clusters of black eggs on seaweed and dead men's fingers. In peak season, you can have a dozen cuttlefish visible simultaneously, and they are remarkably tolerant of patient divers who approach slowly. Beyond cuttlefish season, Chesil delivers rewarding diving year-round. The rocky reef supports a macro photographer's paradise: over thirty species of nudibranch recorded on this one site, from the electric blue and orange colours of Facelina auriculata to the subtle beauty of Coryphella lineata. Conger eels occupy permanent residences in the reef crevices, some individuals known to local divers for years and approaching two metres in length.