I know this is an old thread, but I don't see mention of a possible cause for the spinning, etc, sailors often experience. It's a little different than Meneire's disease, etc, but it's known as Mal de Debarquement Syndrome" or MdDS.

More information can be found at the following:

https://en.wikipedia.org/wiki/Mal_de_debarquement

or

http://www.webmd.com/brain/mal-de-debarquement

This might answer some people's questions ... best of luck!