Although these are pretty big boats - they are no guarantee that you won't get sick in rough seas. Do you know what your tolerance for sea-sickness is? Mine is pretty good (years of boating as a kid) - but I learned the hard way that a commercial operator's idea of ok seas is not necessarily the same as mine from a boat trip on Kauai (a Zodiac in 7-8 foot seas - GMAFB!). I didn't get sick (although most people did). I was just afraid the whole trip that the boat was going to capsize and that I was going to die. Robyn