My MK1 GRP has 3 off 90mm wide stiffeners on the first plank of the hull. The MK1 GRP is a close copy of the wooden originals, they had the same. In my reconfiguration I have been removing areas of the hull that are damaged. Three of the stiffeners were totally saturated to the point that I couldn’t tell what the core was other than in the dim and distant wood. Today I reviewed the others, one was at high twenties relative humidity, considerably drier than the other ones but I still removed it. It was sufficiently intact that I could ascertain it was 6mm ply. The other two are less than 8% relative humidity and are staying.

Just out of interest I weighed her. I have removed about 20kg before removing these reinforcements. Today the hull weight came in at 66kg, not bad for a sixty year old boat that’s had a fair few repairs. The official weight of the Gull is 88 kg so have 22kg to play with. 

The stiffening and bench plywood only is 9kg and I’m sure this will be considerably stiller. Obviously the whole bow area needs stiffening but confident I will be very close to the original weight.