Everything from those wristband-watch type devices that use pulses of electricity to stimulate nerves, to dramamine and other OTC options.
The most effective treatment by far was ginger root powder. You can take it in capsule form and it was the only really effective treatment I came across.
Unfortunately, the principal effect of them seemed to be that people were vomiting ginger-scented vomit. That was a long-ass boat ride; at least half the folks on it threw up.
I like the idea of capsules of ginger root powder a lot more.
Not a cure though, so I've never tried a roller coaster with this technique. The headache would probably make me insane.
If you look for Chimes on Amazon , you can find a 1lb bag for around 15 bucks.
I have been camel sick; large, slow motions.