Thanks
AlanM for the info. Out of glide range of LCY I have seen other less populated possibilities. I think in future I will modify my mental plan and reduce the value of LCY as a bolt hole and increase my thoughts elsewhere including the Thames. I don't go up that way oftern but is quite nice sometimes. Last time I diverted around the Dartford x-ing on the way out and came back through the zone. The time difference was pretty minimal.
Cheers
