Thanks guys
Know of the sugar system. Undecided here. Thanks Wrighty.
Have looked into the drywall/gyprock tape but thought it was not course enough to produce a deep relief pattern. Maybe I'm wrong here but thanks anyway Matt.
Keep the suggestions coming folks, even if I may have offended the GRP boat owners. smile
Hulls look a treat!

Tortured ply is clearly beautiful.
Mozzie Aldebaran VI
1827