This is great! Definitely 5 stars for gameplay. The parameters are chosen very well, to create interesting combat. It shows how strategic old fashioned naval combat was, with all the maneuvering and positioning. (Of course in reality it was even more complex, with wind direction, waves and more complex steering, but it's good that those aspects are simplified here.) The AI is great too. It doesn't play perfectly, but it's challenging enough, and it's nice that it still can be outsmarted.
The roguelike upgrade system is also great, and it's nice that you can also see the enemy upgrades, and adapt your playstyle to it. One thing I would maybe change is the amount of health: rounds take a relatively long time. Lowering the health makes it faster, and more exciting / high stakes.
I made it 7 rounds for now, and then I just missed some shots...I'll probably try again later.
The sound and music is excellent too, very well chosen.