On 22/09/2017 09:29, Chris Green wrote:
OK, that pushes me back towards the hardboard option. It's not *that*
easy to find it though, not at a reasonable price anyway.

Is there no thin marine ply you could cut to size and then get sprayed
by your local car repairers?

I'm sure I could get ply and have it painted but it seems a long,
relatively expensive and rather complicated way to get something very
simple.

You could just remove the existing hardboard next time you are at the
boat, and take it home with you. Give it a stain block and a couple of
coats of paint, whilst working "the right way up" rather than crouched
upside down in the cabin. Then put it back again next time you go.

That's probably going to be the cheapest way to do this, and not that
much work compared to tracking down the material you want at the right
price!