Adds massive cargo ships to the game, that function similarly to trains. Also adds deep sea oil, oil platforms, tanker ships, train bridges and other water based content.
Deep sea oil rigs are currently pretty simple. It might be fun to have them be expandable, especially since you can't really add anything to them given that they're on water. Modules could be stuff like storage (pump oil even if there's no ship to pump to, store on the rig), an extra docking station (to have multiple ships dock simultaneously), or simply increased pumping speed.
