Don't get me started!
I work on a ferry in the North Sea which as you can imagine is not one of the most tranquil stretches of water. Thankfully the summer can give some respite but the winter is a totally different matter.
I've been working at sea for years now but in that time I've sailed with a lot of people who even after years at sea feel absolutely rotten in bad weather. Obviously it doesn't help if you've got a 14 hour passage directly into typically force 8-10 northerly gales (which are very common in the winter up here)
After 2 weeks of that you don't really care how your legs are going as long as it is the opposite direction from the ship.
One piece of advice which is probably fairly obvious but does make a lot of difference to minimise the effects of seasickness is you're far better off on lower decks and nearer middle of ship as the rolling isn't as pronounced, ..................... or better still take a plane!!