The Downs served in the age of sail as a permanent base for warships patrolling the North Sea and a gathering point for refitted or newly-built ships coming out of Chatham Dockyard, such as HMS Bellerophon, and formed a safe anchorage during heavy weather, protected on the east by the Goodwin Sands and on the north and west by the coast. They also lie between the Strait of Dover and the Thames Estuary, so both merchant ships awaiting an easterly wind to take them into the English Channel and those going up to London gathered there, often for quite long periods. In 1639 the Battle of the Downs took place here, when the Dutch navy destroyed a Spanish fleet which had sought refuge in neutral English waters.
It has depths down to 12 fathoms (22 m). Even during southerly gales some shelter was afforded, though under this condition wrecks were not infrequent. Storms from any direction could also drive ships onto the shore or onto the sands, which - in spite of providing the sheltered water - were constantly shifting, and not always adequately marked.
In the present day, with the English Channel still the busiest shipping lane in the world, cross-channel ferries and other ships still seek shelter here.