Originally Posted by
Bravo73
The 500ft rule only applies to 'people or things containing people' (essentially). If there aren't any 'people or things containing people' (and you can be sure of this), then LEGALLY you can fly as low as you like. (The 500ft is NOT with reference to AGL.)
500' lateral and vertical separation between you and people, property, vessels, structures is the textbook definition as I remember it. So anything from pylons to chicken coups fall within that as well as farm houses and cars.
As Bravo mentioned, if you want to operate at <500' AGL that leaves you very little time to set yourself up into a forced landing pattern should the worst happen...especially in light aircraft where you may not have the speed or power to get you to a safer height in a hurry.
Plus the risk of birdstrikes are a lot higher than at medium altitude which don't make for cheap repairs if the airframe is damaged.