Routes may also be erratic since the ships rely on sometimes uncertain weather to plan their itineraries, and also because of the weather, passengers susceptible to seasickness may have some unpleasant moments on these small vessels.
Motion Sickness: Passengers who are prone to seasickness may want to avoid guarantee cabins that could place them in the extreme fore or aft of the ship where the motion is more noticeable.
Larger ships are less affected by the ocean's waves and cross currents, lessening the possibility of seasickness for many individuals.
Someone with a history of severe seasickness might get lower premiums for air travel than a cruise vacation.
Couples who have never cruised before may not want to spend their wedding night battling seasickness.