Not sure if we will see multi-deck ships but I'd love a crafting station meant specifically for boats that lets us customize them to a degree. I'd love the ability to put a canopy up on the longship so I'm not just constantly cold and wet every time a storm rolls in (which happens basically every voyage). Could include other personal touches like the ability to hang shields off the side, or add some form of lantern to the front so it's easier to avoid rocks in shallows at night. Each of these customizations could come with benefits and drawbacks, like the canopy would block rain, but it can also get in the way of you trying to fish like the sail does sometimes. The lantern would need to be maintained to continue working. The shields could offer additional protection to the ship but slow it down a bit or something. Let you choose what build you want for your ship and what purpose that ship is meant to fulfill.