@Daron
It's difficult to recommend a camera without first knowing more about your expectations. How familiar are you with regular photography? how much underwater experience do you have as a diver? how about taking photos underwater?
It's normal for people to see an amazing photo and comment... wow! That's a great photo. If the author of the photo is around, the next question he or she gets is... What camarera do you have? It must be very expensive or very fancy!!!
Truth is, it's not the camera... it the skilled underwater photographer that captured the image. He or she made it happen.
Unlike topside photography, it takes time, practice and dedication starting with diving skills spanning from buoyancy control, navigation and buddy coordination. Nowadays we can pull out a smartphone and in a jiffy capture a pretty good photo. That's not the case underwater.
Light underwater behaves differently and when you add photo equipment, the more features it has, the more complex things get, not to mention keeping things from flooding.
Underwater photography is a fascinating activity. From your post it seems like you want to venture into it while on vacations. You will find it more rewarding if you practice often. The more you dive with a camera, the better your photos will turn out. Practice is of upmost importance. If you are unfamiliar with a camera and you want to start practicing 2 minutes into your dive, your not going to get satisfactory results.
@Imla suggeted you just go and enjoy your trip, forget about underwater photos and enjoy the experience. I think that's the best advice anyone has extended to you thus far.
Please don't think this is an attempt to discourage you from taking a camera underwater. It's actually the opposite. Go to your local dive shop and find who is the camera wiz there, if there isn't one, go the next next shop... you will find someone for sure. Signup for some underwater photography classes, check you local library or bookstore, or see if there is an underwater photography club that you can attend at least a couple of meeting or so. This is a better way of getting into underwater photography.
If you are able to do these things before your trip, you will also know by then what camera is best for you.
Enjoy your trip, have fun and be safe.
Cheers,
Ricardo