[Civilization 5] I've researched Sailing, how do I make a ship?
I have sea-tiles already.
To build a ship or a boat in Civilization V, you must build a work boat in a coastal city. This can only be done after your civilization has learned the requisite technology. For more information, visit http://segmentnext.com/2010/09/24/civilization-v-beginners-guide-part-3/.