The 3rd experiment in the Almabraxas series is expected to be a solar-powered autonomous boat (hence the trailing B). The computer is based on the one from the Almabraxas 2 high altitude balloon. Of course, you can follow the development on the blog.
What speed to expect ?
Here's a page with some hard numbers. In short: it's a 1-2 persons dinghy weighting ~35 kg, 8ft long. Powered with some motor it runs at 4.3 km/h drawing 100W, and 6km/h drawing 250W, so with a well design enough boat, we can expect 2,5-3 kts with 200 W solar panels (assuming an average power of 50% the panel's peak power).
- Scout, the pioneer and inspiration for many of us
- Four boys and their dad (the true essence of hobbyism in my view)
- Solar Surfer
- Sea charger
Not so hobbyist
- MPPT hill-climbing algorithm 
- Solar panels: Amazon, provider
- http://syera.fr/boutique/index.php (french distributor)
Tubes and connections
- Batteries: http://www.buchmann.ca/article4-page1.asp