Airborn by Kenneth Oppel

Matt Cruse feels most comfortable when aboard an airship. He loves being in the air aboard the Aurora as a cabin boy. On watch one night, Matt discovers a damaged balloon with an elderly man in it. As they attempt to rescue the man, he mutters incoherently about a fierce and massive cat-like creature that flies through the air and then dies of his wounds.

As the Aurora embarks on a flight to Sydney Australia, a small air vessel docks with the Aurora and disembarks Kate de Vries and her chaperone. We find out that Kate is the granddaughter of the man who died as the Aurora rescued him. She is set on proving to the world that her grandfather was not crazy and the creatures he was muttering about actually do exist.

In due course, the pirates arrive, a massive storm hits, the Aurora crash lands on a deserted island, Kate and Matt are kidnapped and a romance buds. A terrific swashbuckling steampunk adventure. Lots of gizmos and gadgets are discussed and used, the Victorian era holds strong, and readers are bound to fall for our two heroes.