I've been thinking of ways Civ and make sea units more appealing to use. 1) Reduce the cost of ships by 50%-75%. That's not realistic to real life cost, but since sea units can't attack land units anyways, they won't be overpowered for their cost. 2) Give sea units more available promotions, and allows ships to promote quicker. That way you can vary your strategy. 3) Create a merchant ship unit (worker unit for the sea). You can only trade across the sea if you build a "sea route." That would encourage enemies to use ships to destroy your trade route and you to build ships to defend it. Please think of other ideas that might help. Edit: If Civ uses these ideas, I want a free copy of the new game.