assist assistance buoyancy circle circular flotation device help kisby ring life preserver life saving buoy lifebelt lifebuoy lifering lifesaver perry buoy red and white rescue rescue aid rescue device ring buoy safety safety device security advice alert announcement be-careful beware black care caution communicating communication danger flotation-device information informing kisby-ring lettering life-preserver life-saving-buoy message no-lifeguard perry-buoy personal-protective-equipment pool red rescue-aid rescue-device ring-buoy risk risks risky safety-device sign signage swim swimming swimming-pool warning warning-sign water white