LP below waterline?

[birdboat]

I plan to paint my sailing dinghy’s hull with linear polyurethane (LP). But a few suppliers have told me that LP is not suitable for use below the waterline.

This boat does not stay in the water and it’s never had any type of bottom paint.
The hull has survived with bare gelcoat for 20 years, so I think LP will be fine. Am I making a mistake? Opinions appreciated.

Thanks,
RK

[thefantasea]

Most, if not all manufacturers print a customer service 800 phone number on their labels. Why not call manufacturers until you find one that warrants their product for your kind of use.