Watchet Harbour Marina sits at the mouth of the Washford River on Bridgwater Bay, part of the Bristol Channel, on Somerset's northern shore near the edge of Exmoor National Park.

Operated by Western Marinas Ltd, it occupies the southeastern corner of the harbour and provides sheltered berthing for fishing boats, yachts, and leisure craft.

The harbour is tidal with a significant tidal range of around 6 metres, and both the outer harbour and its approaches dry completely at low water. The entrance, 28 metres wide, lies between two breakwaters marked by a lighthouse and beacon.

Mariners are advised to approach no more than two hours before high water, taking care of the predominantly westbound tidal flow across the entrance. The rocky foreshore fronting the harbour dries out for up to half a mile at low tide.