Here’s a Seahawk helicopter of the Royal Danish Navy undergoing deck landing trials during a storm in the North Atlantic Ocean, near the Faroe Islands (part of the Kingdom of Denmark). From its appearance, I think the ship is a Thetis class ocean patrol vessel. Note that the helicopter stays roughly in the same place in the air, while the ship bounces up and down and from side to side beneath it. It’s enough to make you airsick just looking at it.
Watch the video in full-screen mode for best results.
Back in my dim and distant youth, I once flew aboard a South African Navy frigate in a Westland Wasp helicopter. It was a bit rough that day, but nowhere near as bad as shown above. Looks like it must have been a pretty good cure for constipation for the flight crew!
I can't speak of air sickness, but in my years at sea I saw quite a few flight crews who could not handle rough seas on a smaller ship. They would arrive OK, but a couple of hours later would be as green as the flight suits. I surmise it is lack of a visible horizon that did them in.
You are correct Glen, when you're used to seeing a horizon, you can deal with it. Stick 'em in a can, and it's NOT pretty… That was a test pilot, so that was an easy day at work for him/her! 🙂
Now, THIS one they worked for their flight pay! https://www.youtube.com/watch?v=NJIZTL2ZyEw
One of the Coast Guard pilots at work told me that depending on the length of the ship, the shape of the wave and and depth of the troughs the deck can be rising upwards at a speed of up to 30mph. Having the copilot watch for the lull between waves is a crucial part of the teamwork needed.
And people wonder why I a) joined the Army and b) didn't go to flight school. If the good, solid Earth starts bucking and heaving like that, you have bigger problems.