Before this trip, everyone kept telling me that I wouldn't even know I was on a boat. The night we left Half Moon Cay, the water was really rough - we were sitting at dinner when the boat turned around to head back to sea. I felt really sick for a bit. After about an hour, that passed. We went and sat on the back deck. On the deck below us, there was a kid's pool that had about 2 feet of water in it. Check out the motion of the water in the pool. This will give you an idea of how much the boat was rocking.
After a while, there was no water left in this little pool, it had all sloshed out!
Here is a video of the same pool on the last day of the cruise when we were docked. This is how I expected it to be the entire time. This is how it would have been if we had not been able to feel the boat move, quite a difference.