A Face Mask permit clear vision underwater. It consists of a clear pane of glass or plastic with straps and a form fitting rubber or soft plastic frame. In addition, if chemicals in the water are particularly irritating or dangerous (by the effect of pollutants, an atmospheric taint, or some other conditions), a mask is necessary to prevent damage to the eyes.
The simplest types of face mask appear at TL–5; more sophisticated models, ones that are rigged for full head coverage to permit the use of radio or other special gear, appear at TL–7. For better coverage or resistance to chemicals in the water requires a Helmet.