What is the thickest available neoprene suit appropriate for swimming?
I have a swim suit marked 2/3/4 mm. I don't know which is where, but it was OK as long as the water was about 15 grad, and below was too cold. I know there are apnea suits, which are also good for swimming, up to 5mm. Everything above is scuba dive, and they are definitely not good for swimming.
Is there anything designed for swimming in cold waters?