Good stuff here. Ultra light weight building happens to be my own personal OCD. My Outer Island came in at 30.5 lbs, and using 4 oz s-glass and 3.25 satin weave e-glass is what helped me achieve the results. In short, I want to get as many fibers on the boat as I can while using minimum epoxy, and there are choices in fiber reinforcing cloths out the wazoo if we trouble to shop around, and give serious thought to we're trying to do. I doubled up layers in strategic areas, also used carbon fiber and kevlar in areas that don't show.

How you use your boat is going to make a difference, so plan for that before anything else. Here on the Texas Gulf Coast we literally have to drive 200 miles inland to see naturally occurring rocks, so what works for me may not work for, say, Jay Babina (who designed the boat) up on the northeast Atlantic coast. In other words, one of the reasons I build light is because I can.
http://mysite.verizon.net/NGC704/newOI/Page_9.htm