Compression Failure in Boat Hulls

You can do bkkb. That is a mirror image of bk. use ROM for bk.
Or for plates you can use bkbkb. as long as b is on outside and the combo does not exceed required thickness resulting to overbuild. Carbon is rated at 55 to 60% of ult strength. It will pull down the rest of the laminate to unusable value due to its high modulus and low strain.

I see that the problem is low shear. Shear is most dominant in the web of the stiffiner.

 

Look at strain as defining value. Carbon is at 1.2 to 1.5 elongation (or strain). If you go past that which the basalt or kevlar is capable up to 4, the carbon strain has been exceeded. Carbon will break or conversely, you can only use a limited amount of strain on k or b.