Box calls are easy to use but if they get wet they are useless just like slate calls will be if they get wet. Glass, synthetics and aluminum calls will all work when wet provided that you are using a carbon or sythetic striker. It doesn't have to be raining for a slate call to become so wet that it won't work properly.Dew or other condensation can compromise the slate calls ability to produce a good sound. I would suggest you get an aliminum or synthetic. Im my opinion the aluminum or synthetic do not sound as good as the slate but if you only have one call, you want it to work under all conditions.