Dive-site story
Portland Harbour and the surrounding shoreline in Dorset provide some of the most sheltered coastal diving along the south coast of England. Enclosed by extensive stone breakwaters, the area features a mix of historic shipwrecks, discarded military hardware, and sandy seabed habitats. Divers frequently access shallow wrecks and artificial structures directly from Castletown or by small charter ribs launching inside the harbour.
Protected diving conditions within the harbour breakwaters when open sea conditions are rough
Sheltered shallow historic wrecks, landing craft, and harbour infrastructure
Dense populations of tompot blennies, nudibranchs, and cuttlefish during spring and summer
Location
Use the map to plan with your operator and confirm the exact entry point on the day.
Seasonality
Late spring through autumn brings warmer sea temperatures, increased marine life activity, and better visibility.
Marine life
| Species | Likelihood | J | F | M | A | M | J | J | A | S | O | N | D |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tompot BlennyParablennius gattorugine | Common | ||||||||||||
| Common CuttlefishSepia officinalis | Seasonal | ||||||||||||
| Ballan WrasseLabrus bergylta | Common | ||||||||||||
| Conger EelConger conger | Common | ||||||||||||
| European Spider CrabMaja squinado | Seasonal |
Marine forecast
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