A athletic shirt worn when surfing, snorkeling, jet skiing, or doing other watersports. Most rash guards have long sleeves, and while some women's tops show midriff, most are regular shirt length. They are sometimes worn under a wetsuit or diving suit for added comfort. Not to be confused with a wetsuit or one-piece swimsuit. If there is no line between the top from bottom pieces, assume the garment is a wetsuit instead.