"Avast me hearties! Shiver me timbers and prepare to be boarded," I might say, "as piratical mount 'em up Caribbean! [dev's site] has launched."
I wouldn't, though, because the common perceptions of pirates' speech is a bit wonky and what kind of a monster would spread myth as stone-cold fact? I mean, people who find it funny, sure. And saying "Arrrr!" is fun. Anyway, I would roll with similar facts: Caribbean! (exclamation mark and all) is built on the Mount & Blade engine, and does have Mount & Blade-y gameplay with extra guns and pirates and naval battles boshed in, and it is out. Arrrr!
Caribbean!, obviously, is set during the golden era of piracy. You could play it as a gentle merchant, sure, but wouldn't you rather scamper about the sandbox world murdering everyone as a pirate monarch?
However, do be aware that the initial release has a lot of once-planned features missing. Multiplayer, sea sieges, establishing your own towns, female characters, native tribes, and more all got cut from the roadmap a while back. Developers Snowbird Games explained that their initial plan to simply add fleet action to M&B: With Fire and Sword kept expanding, but they'd never get a release out without trimming these dreams down. So they did. These may arrive in future updates in some form but, like with Early Access, probably don't buy if you wouldn't still be content if the game stayed just as it is.