Lesley - I'll be away back home in two weeks but I've been going along to the over 50s sessions and recently to the water aerobics - all well organised and good fun, with Ian tempering sessions to suit us all. I can firmly recommend both (and indeed other classes with CDA Fitness).
I can also confirm that the water, whilst a little chilly at first is fine for the aerobics class.
Enjoy,
Peter