The invention concerns an underwater vehicle equipped with electrochemical means of electrical power generation, characterized in that it comprises a data processing unit (2) with inputs connected to sensors (4) of a parameter selected from amongst temperature, pressure, and hydrogen concentration, of the water in the area of the vehicle, and of the electrochemical means of the vehicle, and with outputs connected to means (5) of transmitting signals to transmit signals authorizing (or not authorizing) an operator to approach the vehicle, depending on whether the sensed value of the parameter of the electrochemical means is in a predetermined range around the value of the parameter corresponding to water in the area of the underwater vehicle.