We're familiar with the drill now, clamping the keel-spar in place prior fastening? A question arises though as to whether we fill the interior with foam, an option that is facilitated by this latest design which features a keel open at each end: allowing for ready inclusion of fuel, battery, ballast, buoyancy (or selective buoyancy) modules.
We saw at the local pond how triangular sheets of foam can be used here so as to pitch the deck nose up or down while at rest, as an alternative to shifting payload. We have also seen however that the design suffers from an excess of buoyancy that makes it list to one or other side at rest with much of the deck exposed.
Filling the space here with foam alone would displace some 7lb or 3.25kg, which will be useful should we eventually fit 22000 mAh battery-packs weighing some 2.50kg. For now however the emphasis is on minimising weight and running with the lighter battery-packs, and so for now we'll omit the foam.
