I occassionally get involved playing an old computer opponent game but recently I started using the "archipelago" type map because the gigantic size allows the imagination to view the larger land masses as if they are continents.
Anyway I also recently got involved playing a game that uses a simple marker type graphic to indicate the army which can go 2 spaces on land but several spaces on water also (i.e. either/or) as long as there is friendly territory adjacent to the water.

Then also I thought of another game where the land unit is transformed to a boat or ship type unit when it enters water and back to a land unit when it leaves the water, So I started thinking that with the very huge new random maps, that maybe in the new version we could have the "archipelago" type map;
and maybe our units can be transformed into boats or ships when they enter the water and then back to land units when they reach land (i.e. rather than try to create a ship unit that allows units to be loaded and unloaded).

PS:
I apologize for the convolution of the last sentence. I would have liked to put a few quotes on some key words just to make it easier to read and where IMO quotes would have been allowed, but I guess I'm going to have to start writing shorter sentences now also.

TR

A simpler way to do what you're suggesting would just be to make it possible to move across deep water...still very slow going, but still possible.

Travel on land or water by the same unit has been mentioned in my first post, but of course without my helpful quotes, it may be more difficult to find where;
and someone is bound to say that it is not realistic anyway.

TR

navel warfare is a very good idea to me it adds a whole new dimmension to the game.