In reply to jamie_bkc:
I was swimming in Pembrokeshire on Monday and the water felt cold (take your breath away cold) getting in, but was ok after you got used to it. I think the water can feel colder when the air and your skin temperature is so warm.
Cold water shock is a real thing that can kill. If not confident then can be worth going for a dip to aclimatise your body before you start your dws and risk the sudden shock of an unexpected entry into the cold water.
Might be an unlikely occurance now the sea is warming up, but with a potentially very serious outcome it is worth being aware of it.
I'm planning on going dws this evening but my approach to this (much like my approach to trad climbing) rarely involves falling off.