Ferry Boat
A Ferry Boat can be used to cross small bodies of shallow water (8ish coords max).
Source
This building becomes available after once you have learned Ferry Construction.
Cost
Built Outside (Self > Projects > Misc...).
Use
Build the ferry along a shoreline, then "use" the ferry to travel across the water.
When building it, changing the direction of the ferry is purely for aesthetic purposes - the path taken by the ferry appears determined by the landscape (roughly speaking, the nearest shore at 90 degrees to the lay of the land where it's built).
It can be disassembled for a full refund (don't tear it down) with all the parts going directly into your inventory (to be rebuilt elsewhere).