Our team has been working tirelessly to meet our goal of building a completely new boat with which we'll defend our national Promoting Electric Propulsion championship title from summer 2022. Although there is still much to do, here's a montage recap of our progress so far.
The wood hulled boat you may have seen us racing in the past is beautiful, however we had concerns about the structural integrity as we move to building our most powerful electric outboard yet, with about 7x the power of our existing motor. To handle the thrust and the twisting force applied to the transom, we're building a multihull boat.
Our boat started out as a Boston Whaler SuperCat 17, which was given to us by a generous former competitor in the Wye Island CHALLENGE electric boat race. The previous owner was using it to compete with a custom electric motor and some decade old (well loved and heavy) lithium batteries. We knew our new motor would weigh nearly 100lbs more than his electric outboard, and as a catamaran, the transom was already sitting low in the water. Our solution was to integrate a third hull, a portion of a carbon fiber 8-person rowing shell, as a center hull. The original rowing shell was 60 feet long with long tapered ends, so using the first 22 feet of it gave us a sleek bow with minimal drag, with a relatively flat and wide transom (that we glassed in where we chopped the shell).
After joining the three hulls with a 3/4" lower deck, the team began building 3 structural integral battery compartments. Since we were going to be moving from a 48v system to a 144v system (48v x 3), we needed to incorporate multiple features to ensure safety. First, the three 48v banks are isolated from each other in waterproof banks, connected by high current contactors. This allows us to break the high-power battery down into three lower voltage banks in the event of an emergency, or simply for when the boat was not under way.
Stay tuned for more details as the build continues to move toward our June 26th race date!