The origin of the beach has been argued over for some time, originally believed to be from the Budleigh Salterton pebble beds to the west and later from Portland to the south east. The differenced between the pebbles on the beach and nearby sources is now put down to the Flandrian isotactic sea level rise.
The beach provides shelter from the prevailing winds and waves for the towns of Weymouth and Fortuneswell, which otherwise would probably not exist.
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 muddy saline (or brackish) water called The Fleet, which is often referred to as a lagoon, begins. The fleet is home to many wading birds and Abbotsbury Swannery, and fossils can be found in the mud.
The beach and the fleet, because of their proximity to the naval base on Portland, and the low population density of nearby areas was used for machine gun training and bouncing bomb testing in World War II.