Hi! Could anyone help me out with my problem, I'd like to make a carbon bath, but the most nesessery thing about this project is good looks without anything accept carbon and good enough grip so that it won't end badly. If you have any suggestions leave them here please!

Carbon clear yacht finishes are often done with "nonskid" particles in clear paint like Warren suggests - but it looks ugly compared to clear finish. 

Could you mold in a "nonskid" texture using an in (on!) mold clearcoat and then layup over that?  That's a common production boat thing with sticky patterns of nonskid that you cut out and fix to plugs before layup of the tooling.  Each part comes out with a perfect molded pattern.  Might be hard finding a clear that can build thickness like gelcoat.