Thank you for your replies guys. Just to clarify its EU ops i was thinking of and SO it seems I can declare a visual if the cloud base is above top of drop on the ILS and in contact with the ground and I can see the runway when the reported RVR is 800m or above even though the RVR limit for the ILS approach is 1500m. This thought could save a lot of fuel burnt needlessly in the hold waiting.
Does anybody have the EU-ops reference. Andy ?
Thanks again.