The water resistance of the case is ensured by a sophisticated seal system. These seals undergo the ravages of a number of external factors (perspiration, heat, temperature changes, ultraviolet rays, chlorine or salt water, chemicals, cosmetics, dust...). To remain as effective as possible, they need to be replaced regularly. In the event of intensive use in water, we recommend to exchange all gaskets in the frame of a maintenance service every year. Otherwise they should be changed every two years (and imperatively when the battery is changed on quartz models). Generally speaking, it is advisable to have a water resistance test performed once a year (ideally before the swimming season), or else every second year, by an authorized Breitling maintenance center or retailer.