If you're looking for anime similar to Cluster Edge, you might like these titles. All recommendations are made by Anime-Planet users like you!
In the world of Prestal, Noble men perform noble deeds for noble purposes. All of this is performed under the careful gaze of the Guild, a race apart who live in cities in the sky. We see this world through the eyes of Claus Valca and Lavi Head, as their travels take us above, beyond and through Prestal, and their actions cause ripples that shall never fade.
Both Last Exile and Cluster Edge are set in an alternate and fantastical universe. A good action/adventure romp, featuring kids being thrust into a military encounter and fighting to keep the world as they know it.
Both have some interesting air-ships, although Last Exile has much more visually stunning animation. There are also some morally difficult questions posed, meaning these shows are definitely better suited to a more mature audience.