iirc they are naturally buoyant, with the buoyancy being effected by temperature. It's been a while since I read the edge chronicles, but I've been wanting to run something in the setting so I should probably go back through them.
Airship and Floating Island General
Nathan Cook
Parker Martin
I like that. Heat = height. Nice and simple. Get too high and the cool air makes it take more fuel, too.
Orizon has a mix of different flight magics working together. dandwiki.com
Blake Wilson
Dumping airships and related art.
John Fisher
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Andrew Hernandez
I'll join you.
Justin Long
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Ethan Allen
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Bentley Turner
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Jason Long
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Daniel Robinson
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