Like a few of the other posters on this site i have flown in other environments and they are not the same as the N. Sea. HEMS, PAOC, Mil and pipeline all have one thing in common they are all close contact flying with a greater than normal chance of coming to a sticky end. N. Sea is pretty much like an airline and last year on my hols i didn't see one of my plank bretheren with a helmet on or come to think of it an immersion suit. I have experienced some atrocious turbulence on the N. Sea and i have had no concern about bumping my head, if we start getting to paranoid about it you'll end up in an immersion suit with helmet on your way to disneyland.