I do agree with all your comments...
I flew in the Antarctica in the 80's and HF u/s was a NO GO item...
an extra imput...the poor oil companies do have different standards as well...
as it is mentioned ,in Africa they do not have SAR nor budget to cover an expensive" radio operator" ,but at the same time Shell in the Uk (I guess) ...do have at least 24 hour radio coverage...in the dutch sector NAM (shell) is the only oil company having not 1, but 2 radio operators on board the main control platform, 365 days a year, and all other operators during operational hours have a radio operator available, ....
cheers