The harbour at West Bay is not a natural landscape feature and it has a long history of having been silted up, blocked by shingle and damaged by storms, and each time repairs, improvements and enlargements have subsequently been made.

When the railway arrived in 1884, attempts were made to provide the settlement with the facilities of a resort, and today West Bay has a mixed economy of tourism and fishing.

[1] Originally the harbour was about 1 mile (1.6 km) inland, close to the town,[2] and its exit to the sea—the river mouth—was 270 metres (300 yd) east of its current position.

[3] The Anglo-Saxons and Normans struggled to keep the harbour open because the river mouth repeatedly silted up and was blocked by shingle from Chesil Beach, so eventually a system of sluices was devised to help keep it clear.

[12] In 1942, because the terrace had an appearance reminiscent of some northern French ports, West Bay was used as a training ground for the Dieppe Raid.

[14] The railway line between West Bay and Bridport closed to passengers in 1930, and operated for goods services only until its final closure in 1962.

[11] In the second half of the 20th century further residential and tourism-related development occurred around the harbour and old shipbuilding area: new houses were built, old buildings were converted into cafés and shops, and several car parks were created.

[11] After the construction work a small regeneration scheme was implemented, with new housing—called Quay West—built on the west side of the harbour, on part of the old shipyard area.

The cliffs to the east of the harbour are composed of Bridport Sand Formation and Inferior Oolite, while immediately to the west they are Frome Clay (Upper Fullers Earth) and Forest Marble.

The Bridport Sands deposits were laid down in the Toarcian Age toward the end of the Early Jurassic; they are arranged horizontally with clear banding visible alternating between harder and softer material.

[21] The Frome Clay and Forest Marble of the West Cliff are younger and were formed in the Bathonian Age of the Middle Jurassic.

The section of the West Cliff closest to the harbour has been engineered as part of coastal defence management; large protective boulders on the foreshore are backed by a sea wall, promenade and artificial grass-covered slope.

The Eype Mouth Fault, resulting from movement late in the Cimmerian Orogeny (but probably originating in the Jurassic), has a vertical displacement of 200 metres (660 ft) and is aligned east-west, emerging on the coast obliquely in West Cliff.

The coastline faces southwest—the direction of the prevailing winds—toward the Atlantic Ocean, where the fetch length is over 3,100 miles (5,000 km), resulting in the potential for large and destructive swell waves.

[22] The 18th-century construction of the harbour piers interrupted the natural transport of protective sediment along the shore, reducing the size of the West Beach and enabling the sea to more easily cause damage.

The West Cliff is subject to the non-marine processes of slipping and mass slumping, caused by the clay sliding over lower layers and possibly exacerbated by faults within it.

[21] The first section of the West Cliff—and the houses behind it—was protected in 1969 with construction of rock piles, a further sea wall, and artificial sloping of the cliff face.

[22] Assessments by structural engineers in 2001 concluded that, without remedial action, there was a 50% chance of a major failure of the old piers and sea walls within five years.

The production team of Broadchurch was criticised by the West Bay coastguards in June 2014 for filming too close to the edge of East Cliff.

Severe weather and recent rock-slides left the cliffs unstable, and a coastguard volunteer said the production team should have used stakes, safety lines, harnesses, and helmets.