pete,

We used 10mm foam with a layer of 6oz cloth on each side. then cut it to the shape. Normally you use 4mm foam for hulls i think so yes its a very strong frame now... we also cut 2 50mm holes instead of 2 100mm air flow holes so it should be alot better.

We also placed 2 half frames below the front deck to stiffen it up alot

After all of the changes to both hulls the boat still came in under weight