I'm sure there used to be something in the controllers' documents about absolute minima for visual approaches but I can't find it now. In the UK though, the ANO (articles 38 and 39) say that the aircraft can't go through 1000ft if the wx is below the minimum for the approach. Presumably there are minima for visual approaches and whether the pilot can see the runway or not, if the wx is below the minimum, the approach cannot be continued - or am I way off the mark here?
Spitoon,
If you scroll down to the last page of the
CAA Document link that you posted earlier, para 6 reads:-
"A value of 800 metres RVR is to be used at all airports as the Absolute Minimum for visual approaches"