You may consider learning the manual operation (aperature, shutter, exposure compensation, etc.) if you don't know already (and if your camera supports it). It will make you a better photographer - and it's worth the treasures you'll capture.
Amen to that! I haven't been on a cruise yet (SOON

)but I almost always shoot in manual mode in the parks and get much better results than my friends who point-and-shoot. I ended up with great shots of the Electric Light Parade (one of its last nights at WDW

) & the photo at the bottom of my post would not have been possible in auto mode...it was barely possible in manual! Picture me sitting on the groung in front of the flag pole circle, elbows braced on knees, friends holding my shoulders steady, holding my breath and clicking the shutter! (It was a film camera, so I spend the next 3 days thinking "Ihopeitcameout, Ihopeitcameout!")
As a MAJOR shutterbug, my best advise is to really know what your camera can do, carry it around for a few days and shoot in all different types of situations to see what you come up with. With digital cameras, you can trash the so/so photos right away, with film, you can get the photos developed somewhere cheap (BJs,
Sams Club are really inexpensive). To me it's worth the expense to trash a few rolls of cheap film at home in order to get great photos on vacation!