: I'm assuming you meant 4 ounce?

: It's in Nick's book, don't have that here.

: Bill H.

Yep 4oz. I'm looking at nicks book now, pge. 39 which has a table containing relative weights of a Guillemot with diffrent thickness WRC & glass. However, note 3 indicates that he has added an extra thickness of cloth on the bottom which brings the 3/16-4oz combo in at .558lb/ft2.
I just recieved an email from a bloke with the following info:

test panel of 5mm WRC with 4oz in & out. wet out on the inside and filled on the outside. He managed .423lb/ft2 or 2.07 kgs/m2. Not bad. he is building an OC1 that has an area of 4.5M2 with the weight around 9.5kg (excluding rudder system and out rigger. Can't wait to see it.