Don't study too hard! Cruises are A LOT of fun. One thing you MUST do is go out on deck when it's night. When it's dark, the horizon disappears, so all you have is this deep navy blue night sky mirrored in the water. You feel like you're standing in an abiss of nothingness, with only the sound of the ocean and the foam of the water hitting the ship to suggest that you're actually in a real world.
That sounds like it would be so nice. I can picture that. Just wish I could see it.