For cross channel flying,or in "populated" areas, a SART radar transponder might be of more use. If you activate it, it'll show up on every ships radar screen for miles around, and possibly (depending on type of radar) trigger an alarm on their bridge. They can home directly to you using radar.
The amount of shipping traffic is the channel is amazing, (and scary if you're on a yacht, in fog, no radar, no wind, and you're slap bang in the middle of the shipping lanes north of Casquets
)
EA