well i tried all to get shipyard building , but it's icon will not appear in construction bar on excavator in engagement. In champain there is an shipyard icon an you can build ships , but i complet only one stage of champain an maybe you must aquire it from champain. There must be an shipyard to build , beacuse in engagement is a shipyard mark on map when choosing some maps ,so means there is able to build a shipyard , also in maps with shipyard mark , your view gets high zoomed out so it means there must be set to fit ships in . if any body knows anything tell plzzzzzzzzz!!!

You can only build shipyards in multiplayer (online/LAN multiplayer), or you need the Navy Invaders Mod (available from http://uk.gamespot.com/pc/strategy/actofwarhightreason/download.html?sid=6148401)

Can you use lan to play against the pc and build ships? Or do you have to be playing spomeone else?