There won't be any derby points for boat building. The first primary purpose of the derby is to get challengers to use and learn SPOTs idiosyncrasies and how to correctly operate their SPOT. The second primary purpose is to help people get in shape for the challenge.
Side benefits are learning how to pack efficiently and have fun. The derby also helps focus on the goals of the challenge and it's all fun too.
If someone is building a boat specifically for the challenge, I strongly recommend that they enter the derby and keep using a boat they already have. Very often a boat is not finished on schedule. You can never have too many boats so always have a backup.