The Sea Princess is my favorite ship. I hope you love her as much as I do. Not sure what ports you are going to be visiting, so can't really help there. Barbados is a great place in and of itself. We went to the Folkstone Underwater Park the last time we were there. We've also taken the Tiami Catamaran snorkel 6 times, great ships, great crew, really good food. If you like hot food, try the bajan pepper sauce. It's wonderful.
Most of the ports we visit we snorkel. But if you'll let us know what ports you'll be in, we'll try to accomodate your interests.
The Sea Princess is easy to navigate, she's large but not too large. The crew is wonderful, and we've always had great food. They recently upgraded her, so she should be even more beautiful than ever. Best wishes!