I came across this by accident.http://rocketrywarehouse.com/index.php
It is a link to guys who are into rocket like we are into subs.
They have carbon fiber, G10, and G12 fiberglass tubing.
I bought a 48 inch long, 5.5 inch diameter G12 tube, G10 sheet for and equipment tray, and G10 discs in the diameter of my tubing.Wall thickness is about correct for a hull.
For the money, it was worth it!
Shipping was about 10 days, and,after inspecting, I am pleased to report excellent quality. The tube I got is as smooth inside and out as a automotive fender. Nice!
So, if you have a project in mind, this is too good a source to keep to myself