I have used the Relief band for years. In fact I bought a 2nd one when the first broke after many years. To be effective it should be used before rough water begins altho I have used it as seas were building. You have to be careful that you are placing it on the correct spot to feel a tingle in your wrist. You can set it between 1-5 to get the tingle. Very rough seas, I use 4 or 5. Also the band should be very secure on the wrist. I have also used it when nauseated from other reasons. It’s expensive but works & no drug effects.