|It takes 1.5 to 1.75 litters of VC-17 to paint Towser's bottom. You should be able to calculate the area of the deck and topsides from the plan and deck views in Evolution. You'll have to do a bit of guesstimating for the cockpit sides plus an allowance for the curvature of the deck and topsides, but it should be close enough, particularly if you add a ten or fifteen per cent fudge factor.
Alternatively, factor deliberately short and re-calculate what you'll need to finish the job once the second coat is on.
C&C 27 Mk IV