This game is amazing, and as a steampunker, I like it a lot. I was just playing it the other day, my ship got very close to my opponents' ship, and it gave me an idea ...
Why not give players boarding hooks and swords, so players can climb onto the other ship and fight their opponents in some interpersonal battles (like on a pirate ship!)
Or when the distance is close where players can see each other, but not close enough where they could board the other ship, why not let them use muskets (with scope or without scope) to shoot at one another. And since musket is such a slow loading gun, there won't be just a massacre to end a game.