I suppose it depends what sort of fish you're trying to catch.. I'm told that sharks aren't fussy but some larger sport-fish think they're very tasty... Trouble is, the line usually breaks and they get away.
Most people use wind or solar which doesn't tend to attract the same attention...
From RFC 1925: "(3) With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead."