The average diameter of the Agulhas rings is , but they can reach 500 km. They extend down to the ocean floor; circulate at ; and move into the South Atlantic at /day. Only half of the Agulhas eddies that leave the Cape Basin manage to cross the Walvis Ridge and those that do tend to lose half their energy before reaching the ridge within six months. The Agulhas rings transport an estimated 1-5 Sv (millions m²/s) of water from the Indian Ocean to the South Atlantic.