The water on this coastline is generally pretty cold, however (in my experience) not quite as cold as the waters of Clifton, Camps Bay and Llandudno. Big Bay and Blouberg Beach are extremely popular with kite-fliers and kite-surfers, but fortunately these guys tend to keep well clear of the more populated parts of the beach.
When I was youn my parents use to bring my brother, sister and I to this area to swim. Although the riptide can be quite strong, the area has a number of fairly well-protected pools surrounded by annoyingly-jagged rocks (which I remember navigating slowly without shoes).