I edited an anthology that had a pirate story involving non-heterosexual characters, but it was...uh...not exactly the kind of fiction I had in mind with the question.
Well, if it makes you feel better, I started reading Eugenics Wars 1 and you should really ask yourself, “Can I cook or can’t I?” Just don’t tell us you finished it in a day....
To novelization conversation for a moment, I really wish more of them than the Star Wars ones would feature extra scenes. I don't understand why they stopped doing that, it was always the biggest draw for me.
I think it had something to do with readers complaining that scenes from the novelizations weren't in the films -- they tended to assume that anything a novelist added in an adaptation was a deleted scene rather than their own innovation. Or something like that.
Back to pirates for a minute, but then circling back to Star Trek novels... Has anyone seen the 1983 NZ pirate movie Nate and Hays, starring Tommy Lee Jones? A box office flop, but I thought it was a lot of fun. It had a surprising action opening scene, then goes back to tell the story in retrospect. It was apparently released on DVD. I recommend! Also, the movie apparently inspired Lawrence Watt-Evans, who wrote 2 Star Trek novels in 1995, to write a pirate short story, "The Final Folly of Captain Dancy".
It's not a novel, but the comic series "Raven the Pirate Princess" is about an all-female crew, and I don't think any of them are outright straight. It's mostly focused on the young teen market, so it's more light, fun romance, and way more fantasy-pirate than historical-pirate, but I enjoy it, and I like supporting the maritime arts (more or less).
This is definitely an interesting one, and to piggy back off of it other than Lt. Burnham I can't think of any LGBTQ+ characters in trek, any good books heavily featuring an LGBTQ+ character that isn't a discovery book? (don't know enough about it to read a novel really)
In the new PIC novel (The Last Best Hope), it's mentioned that Starfleet C-in-C Admiral Victor Bordson has a husband, but the novel doesn't really get very deep into his personal life too much beyond what Jean-Luc himself mentions in his inner monologues. Also, Captain (and later Admiral) Margaret Sinclair-Alexander (seen in the opening of Star Trek IV, in command of the U.S.S. Saratoga) is established in the novels as having a wife.
The fourth and fifth Rise of the Federation novels feature a trans woman, but I haven't read them yet, so I'm not sure to what extent. There's also Vanguard, which has a queer main character in T'Prynn and another one with Anna Sandesjo, but Spoiler: Vanguard there's some bury your gays going on there
Interesting, I was going to get around to vanguard anyway so I could try that and also rise of the federation interests me