A Pilot colleague of mine says a good indicator of 200ft AGL is the sheep leg rule, if you can see sheeps legs then you are at that height or below !
A technique used in low level training I believe.
Probably totally irrelevant to this thread but interesting anyway !
My view of low level fast jets is "bring em on" love watching tornadoes rip through the lake district at obscene heights, really gets me giddy ! (they must be checking out sheeps legs !) Every time I see one I say to myself " Lucky ba****rd !