Well, as one of the crews that did hear the Mayday and helped relay it to Brest, it certainly sounded serious.
A rather worried Frenchman by the sounds of it making the call. Possibly a turboprop by the sounds in the background. Unfortunately my French is only passable at best and from the speed and anxiety in this guy's voice, I couldnt pick up much. To be honest couldn't swear that it wasn't a ship either.
Relayed that we had heard a Mayday on 121.5 , in French, to Brest. We then heard the guy passing what sounded like co-ordinates and heading to another controller.
Would hope the guy is OK and that it wasn't serious. If anyone knows the outcome, would like to know.
On an aside - if he had broadcast in English, we would all have known what his trouble was, where he was and what help he needed. Might have allowed more or faster help to be obtained if more of the people listening out can understand you. However, I suppose we might all revert to our native language if in dire straits.