I believe the only problem with ginger is that it's a blood thinner. Not too good if one is alreay on blood thinners.
To answer your question - I usually carry a small zip lock bag with candied ginger (found in the spice section of any grocery store) and nibble on it whenever I start to feel queasy. Any type/form of ginger works to some degree (as long as you check the ingredients & it isn't just some sort of artificial flavoring
We were going out whale watching in the gulf of Alaska and were seriously worried about getting sea sick. The lady at the B&B in Seward gave us a bag of the ginger and I've been using it ever since!! It came in real handy...by the way