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, etc.). So that they can be as effective as possible, they need to be replaced regularly. In the event of intensive use in water, we recommend that all the gaskets be changed annually during the maintenance service. In other cases, this operation can must be done every two years (and imperatively when the battery is changed for electronic models). Generally speaking, it is advisable to have water resistance checks performed once a year (ideally before the swimming season) by a maintenance center/authorized Breitling retailer.