For all VFR operations in Class C, D, E and G (OCTA) the 1000ft vertically and 1500m horizontally rule applies. The visibility criteria is greater above A100.
Only in Class G you can operate at or below 3,000 FT AMSL or 1,000 FT AGL whichever is the higher clear of cloud. Also, GAAP aerodromes VMC criteria is clear of cloud also.
Maybe the low level G stuff is to facilitate ag airwork or something.
And ATC are not the police, nor can they tell how close you are to cloud, so it is up to the pilot in command to follow the rule.
Check AIP ENR 1.2-2 for the information.
Cheers,
NFR
Last edited by No Further Requirements; 24th Mar 2009 at 05:30.