From the introduction:
Ariel's feet had never touched the ground. As far as she was concerned, the distant sea was just a reflection of the sky. The islands came and went like clouds, their coastlines no more substantial than water stains on a map.
She turned the screws and the gas jets fired, burning holes in the clouds behind her. At this height nothing in the air could catch her. Her ship was like some exotic flying fish that refused to return to the ocean, its copper scales all green with rust and encrusted here and there with turquoise. One day it would spring a leak and sink to the bottom of the deep blue sky, and she would die, just like everyone else who had ever run aground, but not today. The world was far too big and slow. Just let it try to catch her.