Brighton Baths Health Club (Ocean Enclosure)

Lots of fun to be swimming in the sea, yet within a Victorian-era fence topped with a dock on three sides (the beach is the fourth side). One can enter down steps from these docks or enter from the beach. The dimensions are about 150 meters by 50 meters. Not all sea-life is excluded - I found myself face-to-face with a bug-eyed fish. But, you won't be swept out to sea. It has lovely locker rooms and is very reasonably priced for a swim. The water temp in March was a tolerable 17º Celsius (63ºF).

Apparently it's one of the last remaining examples of caged sea baths! So it was a bit cold and I didn't stay in for long :) It's pretty shallow and there's lots of seaweed on the bottom. There are even lane ropes out at the end for people who don't want to free-swim. There's a steam room for warming up in afterwards and a cafe onsite too. Easy to get to via the beach cyclepath.