Even answering ATC if they can't help you is a waste of time in an emergency. Notice on the transcripts ATC did not ask for those annoying reports on souls on board, fuel, etc, but left them alone to deal with the ditching, probably required if you declared an emergency, or Mayday for the brits.
Mayday is the correct call worldwide. ICAO.
And if ATC did not ask for souls, fuel, etc, then they will no doubt be given a tongue lashing by some brain dead FAA manager who would sh*t his drawers if a bird hit his office window.