I'm thrown out of the site for reading this E-book: "Fatigue in composites". The computer says I reached my limit in reading for free. (book cost about 300 bugs).
So I have to live with what I found so far. Which is quite interesting.

In the book is stated that Hybrid composites ( so for instance glass layers mixed with carbon ones) are slightly more resistant to fatigue then pure mono composites.

I knew that already from my experience with carbon surfmasts. Pure 100% carbon masts break definitly earlier then f.e. 60% masts. I always thought that had to do with more vulnerability from the 100% carbon for impact accidents, but it seems to be fatigue!

So, you understand that I'm happy with my 60-70% carbon homemade cathulls.

Second remark is that they test fatigue in load-cycles with a minimum and a maximum load.
Now I've constructed my hulls (and beams) with a massive core , so the composite skins of the hulls are more fixed, they cannot move.
In a normal cathull the skin itself can bend a little when under load; hence creates a load cycle. (The old nacra's you could push in with your finger on the side)

I remember me the building of a hollow windsurfboard in the far past with only a few internal supports (like a cathull). It was made off 100% carbon and I jumped it in two halves after 3 months.