I don't understand everyone, the point of the ride is to GET WET. I agree with all the previous people, wear swim trunks, change of clothes, TEVAS are great for this ride.
The first year my son and I went on it 6 times in a row so that we could get the water to cascade over us, just once. Not getting wet or the thrill of wondering if you are going to get wet would be TOT without any drops, Dinosaur with the lights on a 5 MPH, etc.
Take the risk, have a back up plan for dry clothes. We always make it the last thing we do at AK.