Pprune is just wonderful, if only for the nostalgia trip. Last known, Speechless One was flying out of Gatwick, initially with Dan Air then, I hope with BA. Where is he now? And as for John Eacott - are you still wearing that wonderful Akubra? Hope 'The Helicopter Company' is still going well.
Back to the main point. Pumas and Super Pumas have had quite a history of falling over, at Aldergrove many years back and, almost as many years ago, when parked offshore overnight (was it the Forties field?) That one I seem to remember was when the wind got up to 80+ knots. Another blown over onshore, after it had been parked as close as possible to the hangar doors, comes to mind again in extreme winds.
The report of this occurrence, with feelings of relief that the pilot is recovering from shock and the co-pilot more seriously but hopefully will return to full flying fitness, talks only of moderate (for the North Sea) winds of 35 kts and the aircraft secured to the deck with lashings. Perhaps ship movement was a factor but it is not made clear if the aircraft had shut down and was restarted. If so and as the French never did fit a proper rotor brake to any of their heli's, the well known wind-up wobble combined with ship movement would be all it takes. You can't beat a Sikorsky rotor brake that let's you start both engines before engaging, with a rapid wind-up when needed.
To add two-pen'orth to the Auto Pilot question, RN training has always made good sense to me - disengage on landing. I seem to recall the odd Wessex tail wheel skidding across the deck as the ship turned after land-on and the heading hold worked very hard to do its job!! Should be SOP for all moving decks.
The technique taught for sloping ground, that the cyclic should be centred after landing, I believe equally applies to moving decks. With the collective at Flat Pitch and the deck moving within cleared limits, there is absolutely no need to try to 'Fly The Disc'.
The Offshore weather and deck movement reports have always required a good pinch of salt, particularly on the RO's change-over day. If the deck movement is - or may become - out of limits then the only way to overcome the intense commercial pressure is to employ those good CRM lessons, provided at great cost by our employers, to say "Diverting" or "I go NOW".
Glad I've been there and done that.