Cloudy Bay is to the east of the Wairau Plain and faces directly into the Pacific Ocean. It was named on 7 February 1770 by Captain Cook while on his way south from the sounds. The Maori name for Cloudy Bay is Te Koko-o-kupe (Kupe's dredge) after the legendary Polynesian navigator and explorer who is reputed to have visited the bay.
The bay's shores are characterised by gently sloping sand or gravel beaches and are only bisected by one river, the Wairau. A diversion from the Wairau which enters near Rarangi was also built to reduce flooding. At the southern end of the beach the White Bluffs separate Cloudy Bay from Clifford Bay while to the north there is rocky headland at Rarangi. Commercial trawling is the main economic activity in the bay but hobby whitebaiting and fishing for cod and kahawai are also popular. There used to be a port at Blenheim but since the advent of roll on roll off ferries at Picton it closed.