We have sailed with seas like that. Got caught between 2 hurricanes! Very unusual set of circumstances. But, took our bonine, aka meclizine and we were fine. We also went up on deck for a while. Scary? A little, but the ships are so big that it just isn't as bad as you might expect. We were getting hit by spray 9 decks above sea level! Actually, in hind sight, it is one of our favorite cruise memories. Quite a rush, but also humbling, to be in the middle of nature's temper tanrum.