You have them swear the solemn oath of the Unforgiven to serve you until the day that they die - having little alternative, they readily accept in a grim ceremony you choose to conduct by the light of a convenient full moon, sealing the deal with their word and blood!
You always did like seafarers - never lost their respect for the Old Ways like some people have these days. They'll make exquisite minions. And the ship, well, you could think of a lot of uses for that, it being a combination of fast, potentially independent of wind and violently hostile to unauthorized boarders. As long as you feed it bits of other ships, that is. It's a tame Free Isles sea monster of some kind, you're given to understand.
You make sure to send word to the Queen that the delegation won't be a problem anymore in the vaguest possible sense, and she rather characteristically seems to have entirely forgotten about them by the time you get around to it.
256 S.I., Fall
The following months are fortunately quite uneventful, which when combined with having a trustworthy lieutenant to handle low-level concerns and elementary surveillance leave you with the unenviable task of seeking the Hell of Ten Thousand Needles, which when combined with the steady stream of exotic texts you've ordered your secretary to collect makes for a great deal of work.
3
The latest batch from the library of a late expatriate of Kudu-Kai appears to be the clincher you've been looking for - it's a long, rather dry read about the various Presidents of Hells Known and Unknown, and one among them is the Hell of Ten Thousand Needles, a mere footnote among the much more popular ones like the Lake of Leeches or the City of Disaster. It is described as a frozen, lonely and desolate place of spiked pillars, and is said to be ruled over by the Duke of Pride and Longing.
To enter, the book goes on to say somewhat vaguely, you need to find a place where the barrier is weak, and offer to the Duke a pint of freshly drawn blood from a virgin of royal birth while chanting his full name (you'll need to work on your enunciation, it seems from the stream of consonants that follows).
A) The Queen's of royal birth and, as far as you know, a virgin (and barely twenty as well, but that's beside the point). Surely she can afford a small trip for the sake of a tome of unimaginable power?
B) You've not inquired about the Queen's extended family lately. Perhaps she has enough of it for your purposes?
C) Best to look abroad, or maybe hope dead King Palthus has some bastards milling around the area and not trouble the Queen about the matter.