A simple and crude way to calculate the laminate thickness of the mast is to assume the mast is an I-beam.
For the graph below I also used the following assumptions:
-Righting moment of the yacht is 60 kNm (see previous posts);
-The mast is an I-beam with 100 mm wide flanges;
-A safe maximum stress (compression/tension) in the carbon laminate is 200 N/mm2.
The graph shows the carbon laminate should be more than 10 mm thick around the upper bearing ( 0 m ).