I've found two different airships now, one after a bit of exploration and the other right behind my starting point (with different characters). I've looked around and apparently you're supposed to be able to buy items from a quartermaster in the airship, including guns (which I've only found one example of in 40+ hours of play).
My problem here is that the pirates onboard immediately turn hostile once I've gotten inside, after making my way up at the anchoring point. While this is reasonable (pirates being hostile), I become frustrated with the fact that all sources of info on these airships indicate that I'm supposed to be able to talk to them.
Best Answer
If you jump into it with a weapon, you'll be immediately identified as a hostile, and killed in moments by gunfire. However, put your weapon away, and they'll accept you inside.