Ships in Darkfall range from tiny simple rafts, to huge 50-cannon warships.
Building all but the most simple rafts requires significant amounts of resources, and a harbor. There are only a handful of harbors capable of building ships in Darkfall, and they only exist in clan cities.

Once you have built a ship, it will appear in your backpack as a figurine. To spawn the ship, aim at a spot on the water and double-click the figurine in your backpack. Keep in mind that once the ship is spawned, anyone can climb aboard and steer it, so make sure you only spawn it in a safe area.

You can climb up onto the ship on either side of it. To steer the ship, walk up to the helm of the ship, and while looking at it, press F.

To de-spawn your ship and make it into a figurine again, press alternate use (default G).