Bonine (meclizine) works pretty good for most people without major side effects. It's cheap when you buy it generic (a bottle of 100 tablets for around $5-10 depending on where you get it from). The patch (scopolamine) which is only available through a prescription does work better but also has more side effects (dry mouth, sleepiness, constipation) depending on your sensitivity to it. Other people swear by acupressure methods such as Sea Bands (non electric) or the Relief Band (electric). I have a Relief Band and tried it on our Navigator cruise but our cruise was so smooth, didn't really get a chance to see if it would work or not.

I carry meclizine and the scopolamine with me on cruises and normally use the patch with meclizine as a backup.

Masaki