If the sea battle system is to work the same way as that of the land battle system, then perhaps we can infer how the new ships are supposed to work.
The following is how I think the ships might work:
- Paddle Speedboats are the Gyrocopters of a sea battle. You use these to counter Balloon Carriers, the sea-battle equivalent of Bombardiers in a land battle.
- Balloon Carriers are used to counter the back-row units. If Bombardiers counter Rams, Catapults, and Mortars in a land battle, then Balloon Carriers counter Diving Boats and Rocket ships, the back-row units in a sea-battle.
- Tenders are the equivalent of either Cooks or Doctors (perhaps a single unit representing both since they fix ships and also supply food and wine).
If you believe I've made a mistake in the way these new ships work, feel free to share your discoveries as a comment below. Have fun experimenting and learning the new Ikariam sea-battle system ^_^.