Originally Posted by
stilton
Understood
I made the comparison as when lifting off from a ship underway in a helicopter you already have the relative wind that would be generated by a rolling take off on land
That's true, but also true of any wind, even on a stationary deck/location. Offshore operations typically limit windspeed to 60 kts, as a function of passenger safety on the deck and also sea state for rescue, but it certainly improves the power margins!