Unfortunatley Flyer thats not an option for some. I have often pondered my little Bell Baby getting quiet after many hours of overwater between Florida and St Thomas. The water gets a bit deep there, but warmer than up near UK Land.
As to ditching there are too many variables to think about to have one pat answer. Calm seas, vs. Rough seas, Engine failure vs, partial . One will just have to decide at the time based on whats available.
For sure its easier to utilize pop-outs and attempt to get the thing upright with blades stopped so you can exit and take all your toys with you.
That opens another bucket of worms as to what your going to have for survival, as the heli heads for the bottom..