The Bright and Breaking Sea – Chloe Neill
TBaBS is an alternate-Napoleonic-War novel - except that the sea captain is female and has some magic, the monarch is female and sane, and many names have been altered. (E.g., France is called Gallia.) Other tropes, such as the attraction between said captain and the handsome Viscount will also be familiar. The Queen sends the two of them hither and yon on confidential (and dangerous!) missions. The missions are consistently successful.
The missions are consistently successful because the author is always willing to provide a plot device to get the heroes out of trouble. For example, Kit Brightling’s sister is a genius inventor, and can provide Kit with gadgets, as the story demands. The book was was fun to read, but it was self-indulgent, and for that reason it left a bad aftertaste.