My favorite sea map was the Caribbean from age of empires III. Everyone would start on a separate island and there'd be another island with treasure on it.
We need to surrect a clone of @Stan` to improve the ship models.
1. Reduce their size by about 20%. This requires their animations to be re-exported. But would definitely help with pathfinding!
2. Ramming Ship animations. Something akin to the battering ram actor moving back and forth, while the entity itself doesn't need to move. The whole affect only needing to occur in the animation and no need for new unit motion code.
3. The Roman and Carthaginian Quinquiremes are pretty ugly compared to the Ptolemaic one. Probably just need an all new model.
This kind of attitude prevents improvement. Siege Towers are pretty weird at the moment, but because some folks have managed to use that weirdness to their advantage we shouldn't improve them?
At least one good random map for naval play is sorely needed. Something good enough that it could be played semi-regularly in rated. There are some great skirmish maps, but they are mostly limited to 1v1 or 3 players.