Re: What causes seasickness? Is it in the head? The stomach? what?

Seasickness is all in the head.  Actually it's in the ears.  There is a complex 
of three fluid-filled canals in each ear that communicate with the brain and 
eyes to help us maintain our balance.  Out on the water in a boat these canals 
send many more messages than the brain is used to, from the constant bobbing 
around.  There is so much movement that the brain gets confused and nausea 
results.

Like any other organ, however, with time, the brain gets used to the complex, 
multiple messages and gets used to the increased number of signals and the 
seasickness goes away.  This, of course, varies from person to person and can 
take from days to weeks to get better.