A couple of weeks ago, I heard a D reg cessna calling Shoreham from mid channel. He was not far from Seaford and kept calling out but, he was that low, Shoreham couldn't hear him. His messages were eventually relayed by a helicopter and he revealed he was down to 300 ft and heading towards the coast. There was at the time quite a bit of sea-mist in the channel but hardly any at all inland. He made it and climbed up to 1600 shortly after crossing inland where it was clear. I wonder exactly how low he would have gone before doing something about it.