Thanks for your help! The rib in question is not one of theese high quality Scorps, I have never heard that they brake.
I looked at the cobraribs, they look like any other leisureboat to me, Avon has a bad homepage since i can not find any bigger Avon than 8.4m. Ribworker looks great, but heavy. 38 knots at full bore. That would normally be 30 cruising knots. That is a lot slower than the high speed ferry cruising at 38 knots in our fjords.
In fact i think that my customers might just as well by a ferryticket! But Ribworker is a really great boat, which would last foerver, and set up with a surfacedrive and 1m. shorter hull, the speed would improve.