Daring swimmers of all shapes and sizes will take the plunge at midday sharp on Saturday, and the pool is open for hardy breast-strokers from 12pm till 1pm. Expect acres of exposed, horripilated skin to be on display; luckily the cafe is open all day, dispensing plenty of hot drinks and warmed mince pies to bring the body's core temperature back up again.
Though the idea of al fresco swimming in the bleak midwinter may not appeal to all, it's the last chance you'll get to swim at Brockwell until the summer season opens in May next year. And winter swimming has its health benefits: as Olivia Brown of the South London Swimming Club told us last year, "cold-water swimming is the best prescription for happiness". You've no excuse not to go.