Thank you Bill for your response!

I was not sure, how far I should increase the boat width.
My current beams are made of carbon pre-preg, are 2.5m wide and have diameter of 16cm, they come with no dolphin striker and are incredibel stiff.
I will build the new beams with carbon and a vacuumpump, by my own. I have never done that bevor. As much as I know is, that the strenght of pre-preg is higher than standard carbon laminate.
Now that I'm not a engineer and I can't calculate the forces and the strenght on the new beam.
I thought that applying so many layers of carbon, until I achieve a wall thickness of 115% to the old carbon pre-preg beam. In this way, there should be some reserve of stability.

Also the local supplier of carbon fibres, told me, that when I feel, that the new beams are not stiff enough, it is easy to apply some more carbon layers later, to increase the stiffness.

I'm thinking of mixing carbon-braids, the first layer standard carbon crosswoven, the inner layers undirectional and the outer layers crosswoven again.

What do you think? Will this work?

thanks again for your post!
greetings from switzerland
Andi