Life Jacket or Life Vest - A floating equipment that helps keep the user afloat - preventing them from drowning as they jump into the water during emergencies. They can be found on airplanes, cruise ships, swimming pools, and other venues that involves water sports activities. Sailing Jacket or Waterproof. The integrated Deck harness is certified to ISO 12401, making it an ideal choice for anyone looking for a safe and reliable life jacket for sailing or racing. Furthermore, the hammer system's manual inflation and hydrostatic automatic release mechanism keep you from inadvertently inflating in extremely wet circumstances.