I have the following vision (for an expansion pack obviously):
- You can build harbors and shipyards if cities are located near beaches, as in WOM
- You have transports and warships, and an own unit designer for ships as well. Techs that gives new equipment for ships etc must be implemented in the tech three. Alternatively new tech could make new pre-made ship models available. Different kinds for kingdoms and empires.
- Transports can transport an army, but are nearly defenceless. Warships can be used to kill transports, escort transports, blockade enemy ports etc.
- Tactical battles are not between armies on a ship HOMM-style, but warships fighting it out, and transports trying to survive. Moving an army over the seas is a risky business. Feel the excitement of taking the risk, scout for the enemy fleet, where can it be? Will our invasion be noticed, and perhaps intercepted?
- Champions and Sovereigns can learn navigation skills and certain artifacts should give bonuses to seabattles, sea movement, and to fighting seamonsters
- Navies can appoint one champion as an Admiral. His sea traits gives bonuses to the fighting fleet during sea battles. The rest of armies on board are sitting ducks if the sea battle should be lost.
- The sea will have it's own specific creatures, monsters and quests. (Some you must bring a land army to fight, some you engage with your war fleet (earning experience for your admiral))