The size of the shingle varies from pea-sized at the north-west end (by West Bay) to potato-sized at the south-east end (by Portland). It is said that smugglers who landed on the beach in the middle of the night could judge their position by the size of the shingle.
From West Bay to Cliff End the beach is piled up against the cliff. At Cliff End a hollow forms behind the beach and at Abbotsbury a stretch of saline (or brackish) water called the Fleet lagoon begins. The Fleet is home to many wading birds and Abbotsbury Swannery, and fossils can be found in the sand and mud.
Because of the low population density of nearby areas and their proximity to the naval base on Portland, the beach and the Fleet were used for machine gun training and bouncing bomb testing for Operation Chastise in World War II.
The origin of Chesil Beach has been argued over for some time. Originally it was believed that beach material was from the Budleigh Salterton pebble beds to the west and later from Portland to the south east. The differences between the pebbles on the beach and nearby sources is now put down to the Flandrian isostatic sea level rise, so the feature could also be considered a barrier beach or bar, that happens to connect the mainland to an island rather than a 'true' tombolo. Normally, tombolos are created due to the effects of the island on waves (through refraction) and to sediment transport, which usually produces a beach perpendicular to the mainland rather than parallel to it.