doggie said...
The FireWire website has a volume calculator on it and it works very well.
I reckon the calculator is a bit on the high side.
The volume it recommended for me results in a 2 3/4 thick flexfire. That would be a boat.
Sometimes volume is a bit counterintuitive....once you get too much volume in a board it becomes a boat and gets stuck in the lip on takeoff. 2 1/2 is generally an ok thickness for most surfers.
Mals are a different story.