As you leave either of the Universal Orlando Resort theme parks, be sure to have your hand stamped as you exit in order to be granted readmission into that park later in the day or evening. In addition to the hand stamp, be sure to retain your ticket stub. The hand stamps are designed to be water-resistant, so don't worry if your hands get wet if you choose to return to your hotel in the middle of the day to go swimming, and then want to return to Unversal Studios Florida later that evening. Try to refrain, however, from scrubbing your hands clean with soap until your day's visit to the theme parks is complete.