Ever since Louisa Carmichael's brother unexpectedly inherited a dukedom, her mother's expectations for her have veered in a distinctly vertical direction. Louisa dreams not of glittering ballgowns, but of exploring the tropical waters of the Caribbean with her latest invention, an underwater breathing apparatus.

When her mother arranges a marriage for her, Louisa decides she might just don a pair of breeches and discover the Caribbean in disguise. The only problem is a certain very handsome captain...