Back to the actual topic...
Canoes and Rafts would be great. As far as anything larger, I personally wouldn't push past a 21-footer, seeing as how every Tom, Dick, and Harry is going to want at least 1 ship for their tribe. And on top of that, if they do go for a 21-foot ship, they should make it so it takes a few people to crew it... like 2 to 4.
Also, canoes can store some things, just like rafts. You will just be limited more when it comes to space. However, canoes would probably have an advantage over rafts, if water-flow was ever implemented. Rafts typically only move downstream, where canoes can go downstream or upstream.