I want to add a few things I've learned about cruising & diving:
First of all, if you are cruising to DIVE, that's definately doable and can be a great time. You will be motivated enough to figure out a way to keep a good attitude about all the gear everywhere, and schlepping your gear back and forth to dive ops, and you won't mind because you're ultimately going to get in some great diving. If you're diving some, because you're there to CRUISE, that's also going to work fine. You might want to use a bit more rental gear to cut down on the stateroom mess, since diving's not the primary focus, but that's personal preference. We haven't paid the extra $$ for a balcony, yet, but I'm sure it would be great. We've just been too cheap to do that, would rather have the $$ and just work a bit harder to stay sane in the stateroom.
To me, cruising is the "sampler platter" of vacations, whether diving or not. Our first tropical vacation was a cruise, we loved it, especially because we got to have fun while someone else was taking us to a place we'd never seen but always wanted to, basically hassle-free travel. We got to snorkel in our first blue water (Roatan) ever, and fell in love with the whole experience. Then, you get back on the ship and have more fun while someone else has the hassle of taking you to another exotic location that you've always wanted to try. We've been able to experience places that we probably would never fly-in without trying them out first during a cruise ship stop. For example, I had always thought I wanted to fly to Jamaica, but after visiting there on a one-day stop- I'm glad that I've been there, but I now would not spend fly-in $$ on a trip there. We found that we would much rather be in Cozumel than Cancun, which, prior to cruising, I thought it would be the other way around.
In other words, for us, cruising introduced us to a whole lot of options, and we've been able to make more informed choices for our personnal preferences in regard to fly-in vacations. For a lot of people, scheduling dive ops in an new/unknown location can be a bit intimidating. But once you have visited that port, even for just one day on a cruise ship, you have learned a lot about how to get around, what the taxi/crowd situation is like, etc. It makes it much easier to have the confidence to do your "own thing" on subsequent trips. For that very reason, we try to book our own dives in a location that we've visited before, and use the ship excursion's op in new ports.
We HAVE learned that we personally prefer fly-ins for dive-purpose trips, but we will certainly cruise if the right opportunity presents. We did a diving cruise this year with our LDS, and while hectic at times, the commadarie and fellowship we all enjoyed made the extra effort worth it. Plus, the after parties rocked. ;o)
Foo