There is a disorder called Mal de Debarquement which literally means sick from disembarking. People with this condition are usually female and middle age. The condition is diagnosed when that rocking feeling continues for at least two weeks or more after a cruise and all other inner ear or vestibular illness is ruled out. The condition is either very rare or very under diagnosed since most regular docs and ENT docs are not familiar with it. In most cases of Mal de Debarquement, the patient recovers, however some people have this disorder to some degree for many years. People prone to this disorder usually report feeling that rocking feeling after every cruise they have gone on, with it lasting longer after each cruise until the one time that it doesn't go away. I have had Mal de Debarquement for about seven years now and am lucky that I am able to control my environment enough to keep a manageable level of baseline dizziness instead of full blown rocking most of the time. That's a good thing, because I refuse to stop cruising. I have found that taking Meclizine (Bonine) twice a day on sea days makes my full blown rocking last for a much shorter time after I get off the ship. If anyone has any questions about Mal de Debarquement, I would love to hear from you.