Welcome to Cruisemates & nice to see you have cruise fever! It's not crazy to book the crusies that way, if that is what works for you and your family. Your husband may not even be effected by sea sickness. The stabilizers do a good job, & many who think they will, are surprised with no symptoms, but he can look into sea bands and ginger, if he feels he wants tovcover his bases.
Why dont you look into renting an electric scooter...this may be your answer to being more comfortable in ports. These companies can deliver to the ship,and give you peace of mind.
SinceIi have never booked onboard, I will leave that answer to the others who will post.
Contact a cruiser specialist travel agency, to get the most info, to help you book your cruise,and ask about travel insurance. Let us know what you decide, and, we can help you more, while you wait.!
Trip, with her book & tea!
Chat Hostess & Board Moderator