Some myths being bandied around re D&D coverage. The 3000 feet coverage that often gets generalised is for accurate DF fixing not RT coverage or SSR/PSR coverage. As for RT coverage over the channel, I had cause to put out a mayday call a couple of years ago in the Abbeville area at about 1800 feet on 121.5. It was picked up very quickly and emergency services informed....all by D&D at London Centre
Moli