I think one thing depends on if anyone in your group gets motion sickness. If they don't, you might want to have something handy to start taking immediately with the onset of sea sickness. They do have medicine on board in case you forget or run out. You can use the wrist bands, bonine, dramamine (less drowsy), a patch (I think your doctor has to prescribe this???)or from what I hear, there is also a shot you can get ahead of time. I'm going to look into this before our 7-day. I get very sick when there are storms.
I did the best taking 2 dramamine. Unfortunately, I had only taken 1 earlier in the cruise and it wasn't as effective during the first storm on the first night. I thought it would make me sleepy if I took 2. I got brave and took 2 during the second storm and it really didn't make me tired.
Also, my asst. server brought me crackers and ginger ale during dinner the first night and it really did help.