walter kennedy,
I’ll bet yachties and fishermen at sea level would be surprised if there was no VHF coverage in that area let alone at 500 feet
I have both sailed and flown in that area. I would not be in the least surprised if there were large holes in the marine VHF coverage. It is common to hear yachts acting as relays, especially for distress calls- in fact, the most common craft involved in rescuing yachts in distress is other yachts.
However, marine and aeronautical VHF operate on discrete frequencies, and with differing coverage specifications. Marine VHF works on the basis that most antennae will be at less than 100' above sea level, and many will be less than 20'. The Coastguard and coastal radio stations are located to deal with this. Furthermore, the shape of the coastline means that an antennae mounted on Islay can provide surface coverage a surprising distance up any number of the sea lochs.
Aeronautical VHF, on the other hand, assumes that any aircraft other than circuit traffic will be at an altitude measured in thousands of feet, instead of a few dozen.
Your closing comment,
so betraying the people of Northern Ireland
is revealing. At last your motivation for pursuing the sabotage theory so doggedly becomes clear. It seems you have more interest in discrediting the peace process in Northern Ireland, than in clearing the names of the crew of ZD576.