A method of chlorinating drinking water on a ship with a production and distribution system includes a recirculation distribution network and device for injecting a chlorine compound generating free chlorine into the network in an injection point. A regimen set point is set for free chlorine concentration at the injection point between 0.4 and 1.2 mg/l. Free chlorine concentration is monitored proximate the injection point by a first probe. Free chlorine concentration at a point furthest from the injection point is monitored by a second probe. The chlorine compound is injected into the distribution network to maintain the free chlorine concentration at the regimen set point. Regimen chlorination is performed if the second probe does not detect free chlorine concentration variations from the regimen set or detects variations in concentration relative to the regimen set point lower than a safety limit and/or duration lower than a safety time limit.