Agreed for the world gen. A dugout would be a middle ground between the raft and the sail boat. I think the utility of a dugout, depending on how big it's made (if its only 2 slots, it'll be worse than the raft), would be countered by the time cost of having to burn and scrape out the interior. It could also be scaled, with one being able to do 2-8 logs and have a canoe of the size you want, with speed penalty or the inability to really pick it up for a portage after 3 logs. Being able to have a watercraft that has multiple slots would be great. It could also be expanded into outrigger canoes and outriggers with sails to add more middle ground between the raft and sailboat.
Hopefully since they are planning to add rivers, dugout canoes make perfect sense to add then as sailboats aren't a massive river thing, and if rivers are added, we'll hopefully get more bodies of water and improvements to fishing (such as nets, traps, or the automatic salmon catchers).
https://upload.wikimedia.org/wikipedia/commons/e/e4/Dugout_canoe_manner_boats_de_bry.jpg https://upload.wikimedia.org/wikipedia/commons/thumb/e/e1/Pōpao.jpg/1920px-Pōpao.jpg https://upload.wikimedia.org/wikipedia/commons/thumb/1/18/Südseeabteilung_in_Ethnological_Museum_Berlin_11d.jpg/960px-Südseeabteilung_in_Ethnological_Museum_Berlin_11d.jpg