Don't use kevlar on the outside. Kevlar has low compression strength, it is difficult to fair, and it is not very UV tolerant. On the positive side it has very high tensile strength, it is lighter than carbon, and it resists crack propagation. Use Kevlar on the inside or as a core in combination with carbon or glass. I use it on the inside of wood composite and as a core with carbon for things that are subject to impacts like rudders and dagger boards.

If you want to use something on the outside for protection, try glass. I use a 4 oz fabric that looks like satin dress material