RE: brushless pvc sub
Now would be a great time to find a plastic Easter egg to use as a nose. It's a good shape hydrodynamically, light weight and cheap. If you want something sturdier then use it as a mold for the fiberglass nose. Lay up the fiberglass on the inside of the mold and it will take up the smooth finish. That will save you a lot of sanding!
What diameter are you shooting for?