I don't have my cruise documentation in front of me now, but I was going over it last night and there is a part that mentions a NO WEAPONS policy. I did not read fully, as we never have anything that could be mistaken as a weapon, but I'd think the knife would qualify. I'd say, better safe than sorry and to avoid any unnecessary attention, I'd leave it at home. Will you really need it on the cruise? How have you found traveling with it since 9/11? Have they given you grief at the airport? I can tell you, they would not allow you past security at either SJC or SFO with a knife. You COULD check it. I'd ask myself if I really needed it and if I didn't, I'd just leave it at home and not worry.