This game exists and it costs
CHF 2.50
See also
here.
Edit: Oh I just saw you were aware of the Ironclad series. Why do you say it's not a good game? The real time naval battles are the best I have seen in any game, I can only think of Rule the Waves of coming close in regards of realism. I find the strategic map mode a bit cumbersome to navigate but the mechanics as such seem realistic and useful to me.