Dorothy Dunnett, Dolly & the Singing Bird. Actually, ALL the Dolly books have pretty unreliable narrators, but Singing Bird is the best of those. Or maybe Dolly & the Bird of Paradise, to a somewhat lesser extent.

If you haven't read them, they're mystery/thrillers written & published out of internal chronological order but set in the year each was written (which makes your head hurt, I know), all narrated by a young woman who has an adventure with a British portrait painter/spy named Johnson Johnson and his yacht Dolly.