There are non-drowsey motion sickness tablets - check at the drug store.
There is no complete answer to the weather and sea state but May is generally ok with the more inclement times still to come. As mentioned there are non-drowsy tablets available and as a precaution you should take some with you but do not assume that you are going to feel ill. So many people are very surprised as to how well they are feeling on the modern ships. One of the recommendations by the way is that you should eat ginger in various ways as a steadier of the parts affecting seasickness. I am sure you'll be ok and like everyone else put on a few pounds.... Neil.
Thanks again for your advice, Neil you answered a question of mine a few days ago about storing luggage on last day of the trip, you didn't answer the second part of my question which was "What time will we have to disembark the ship on the last day?" The ship is the RCI Liberty of the Seas
They do like to clear the ship fairly early so that they can prepare for the next onslaught and I would consider that 9-30 will probably be as late as you can stay but it's a guess and you may just get a half our on that. .......Neil.
Thats not bad! I watched a Sky Travel video Cruise diary by Steve Read and stated that he had to be off the ship by 6.30! I hope your answer is nearer to the actual time than that!
Thanks again for the info.............. M Ellaway.