How did you get on with last weeks question?
Quite an easy one if you know where to look.
MSN 1837 (M) Categorisation of Waters
I could have been nice and give you the answers but then I run the risk that you might not go and look it up for yourself.
Why is it important? There are some areas where the Cat. changes between winter and summer as do the geographical limits. I know of a couple of instances where people have unwittingly gone out in winter blissfully unaware that their insurance didn't cover them.