Based on my understanding and experience, the vast majority of people will not have any kind of sea sickness problems on a large cruise ship. It seems to me that most of the people that worry about this have never been on a large cruise ship before, and in some cases, are using this issue as a reason to avoid cruises because they don't think they'd enjoy them for other reasons. I've been on a dozen cruises, and can't think of a single situation where I've observed or even heard of someone onboard having sea sickness issues. I have seen lots of sea bands worn by passengers, and behind-the-ear patches. How many of those were effective because of what they actually did, versus the placebo affect, versus the person using them not being prone in the first place, I have no idea....................