Footy - Building it Light Weight

A friend and I recently built Brett McCormack B-2’s and his came in well over a pound (6 to 8 oz over) and mine was just under a pound at 15.7 onces. Mine was modified for a higher freeboard and uses lithium cells. He did use basswood and our ballasts are in the same weight range.

I would like some chatter (this site is good for that) about techniques for building it light. I hear about some boats that seem impossibly light weight.

Things like:

Hull Material (I used 1/16 balsa)
Sealing the wood inside hull (I sprayed a clear lacquer)
Outside Primer (Spray primer - Many coats to fill voids)
Outside finish (still in primer)
Power Switch (I just brought 3 small pins thru deck for charge/on/off)
Battery Case - (None - I just soldered batteries together)
Servos (HS-81 for Sail and HS55 for Rudder)
Deck Cover (Just Painters masking tape now, but monocoat final)
Rudder Servo Rod (1.25" long stainless wire with servo near rudder post)
Sail Arm (1/4" x 1/16" carbon fiber flat stock)
Hatch Cover (Jenny Craig Soup Bowl Rim and Cover - .4 oz)
Tried to minimize internal supports
Rigging (McRig)
Z-wire (Bike Spoke)
Mast Tube (Aluminum)
Mast (3 mm carbon tubing)
Boom (<2 mm carbon rod)
Sail (Kite Material - Icarex PC-31)
Keel (Balsa with two pcs of carbon flat stock sanded to airfoil shape)
Keel Trunk (Only 3/4" above bottom of boat)
Ballast (Custom lead weight at 6.1 oz and sealed w/appliance paint)
Rudder (Balsa with Carbon Post and Carbon Sleve)

I await responses.