We discussed placing ballast in the keel space like batteries, though it might result in undue 'pendulous' stability in something designed for banked turns.
Larger bells often feature a counterweight, fixing ballast above the axle to make them easier to swing: a battery up top would have the same affect, bearing in mind deflection of the rudder surface ideally applies roll and yaw in the desired direction. Transferring mass below the axis would result in less roll, and a flatter turn.
One reason for focus on this design and not the catamaran is to mimic the motions of a water-skier on a slalom ski, or a motor-cycle instead of a car. Somewhere an author waxes lyrical about the beauty of a banked turn that can only be experienced on two wheels instead of four and I'm thinking it was 'Zen and the Art of Motorcycle Maintenance'.
The bell is from Barcelona and pictured upon removal for renovation... kevlar straps were only rarely used by master builders in the Middle Ages.
