At one point I had worked out (in my head) a deployment style...maybe I mean battle scenario that represented a battle between two armies on the high seas.
It required building two rather large** ships. I think the deck dimensions were 60 inches long X 20 inches beam (width). Very tubby 3:1 hull ratios.
It worked as follows:
The ships were setup parallel to each other.
All warmachines were deployed to fire from the broadside into the other ship.
They would shoot during the deployment phase as the ships edged closer. Meanwhile units would be forming up on deck (deploying).
Within 3-4 turns the ships would meet at the table center, bulwark to bulwark.
Then a pitched battle would be fought raging from deck to deck.
Essentially the ships functioned as giant move trays or mobile deployment zones.
If you are willing to switch from Warhammer to the Lord of the Rings system (which in my experience works pretty well and suits ship-to-ship combat, i.e. unformed units, much better), there is the Warhammer Historical book on Pirates (Legends of the ...). This has rather nice and easy rules for ships and are as far as I remember fully compatible with the normal tabletop rules and pace.