RE: Do you need to cover blue board?
I go along with dadaddyro. Glassing it over adds at least 200% more strength to the hull. In essence, forming a shell.
For a low powered hull you may have no problems with durability. But then there is always the ever present dings and dangs that happen just in handling the hull that can surprisingly damage the hull to a point where it has weak spots. I'd hate to see a hull disintergrate on the water going wide open.