Normal
The Atlantic waters can be rough and it depends on the time of year. Yes the size of the ship means something as far as how much movement you will feel. But if the seas are rough you will feel them on any size ship, just maybe not as much. Maybe your boyfriend should consider wearing a motion sickness patch. He can ask his DR. for an RX for it. If not dramamine and others like will help. The key is to take them before he gets sea sick not wait until he is sick. Good luck and most of all enjoy your cruise.