Hi Wyern,
You can probably find some of the information about solar & battery requirements at links like this:
http://www.tamarackelectricboats.com/
The owner of this company is a member of one of the local electric vehicle lists I'm on. (He also just placed his order for an
Aptera EV.)
http://www.transatlantic21.org/boat/
This one crossed the Atlantic last year on solar power.
You may not be going for that scale, but there's information on both sites that will help you figure out what size motor, battery bank & solar array you may want.
I don't have a lot of experience with electric boats. Here's mine:
(
details about my e-boat)
Doesn't sleep 4-6 people though
EDIT: this summer I made a solar powered boat:
Details:
Fun weekend project: solar assisted electric boat conversion