Nice report - For a puddle dive
Thats a lot of weight to lose. Are you wearing the same undersuits etc that you wear in the winter? Is this on your Twin 10L?
Mind you i only need 4Kg in the sea this time of year on my twinset, bit more on a single 15L though.
Bit more up North though, a 5 Degree difference between St Abbs and Dover in water temp, so more baselayers.