Just make sure your carryon will fit the overhead requirements. Tripods are ok. I have started putting my adventure 9 backpack inside a small rolling suitcase. If no laptop, you won't have to open anything up. Easy on me and helps give extra protection in overhead. Plus no one will ask you to put your backpack under the seat. As far as the cruise, I've been on about 40. Agree with lens recommendations above, including taking the 50. Will come in handy on board for vaca snaps, especially in dining room, where you will want your flash as well. On shore, one lens on the camera and the other in a belt case or fanny pack. Whether tripod is practical depends on what you do on shore. If on your own, no problem, if on an excursion, you may not have time to set up shots, so hand hold and do your best. As someone said, if rocking boat is a problem, you won't be thinking of shooting. I've never had seas that rough cruising, but your itin is going to hit some open seas. Even then, unless they hit a storm you will be fine. Anything else, just ask.