Steve Firth wrote:

The rubbish sold in DIY sheds as "yacht varnish" isn't suitable for
continuous immersion. It's not even proper yacht varnish.

What about International Yacht Varnish, as sold in B&Q? Genuine question
- I know of International as a pukka manufacturer of marine paint,
although not having a boat myself I don't know any of their individual
products.

Pete