I have had great luck with Ginger capsules that are available in any health store. they settle the stomach and have no side effects. they really do work.
some years ago there was a product available called TripTone that worked on the inner ear rather than the stomach, and thus did not make you sleepy. if you do fine the product, check the ingredients to be sure that they have not changed to a stomach sedative.
I just returned from the Ocean Princess and was sea sick the first nite. I went down to the ship's doctor and received an injection and sea sickness medication) by perscripton) and then went to sleep for twenty minutes. I woke up cured! it was great. It cost some money to see the doctor but if you get the insurance it should be covered. It was worth the money because nothing else helped me. I bought those sea bands to put on my wrist and the ginger tablets also. they did absolutely nothing for me!