Thanks for the replies.
I got a couple of these http://www.bcf.com.au/Product/Blueline- ... 0mm/168324 for Christmas.
They are very comfortable , but don't quite fit with the curved back of the cockpit seats, I have attached one to a plank, to tie arthwartships across the pushpit to make a "Dickie seat" facing forwards. It will need to be easily removable, so the outboard on the transom can be operated.
These cushions come with snap buttons but don't really want to screw them into the fibreglass cockpit seats.
Do you find the cushions you have fall off the seats?, or do you have a way of keeping them in place? (Velcro??)
cheers