Abstract: The rescue-unit includes a housing containing, a folded floating element and a bottle of compressed gas for automatic inflation of the floating element in the water. Inflation is initiated as soon as disc-like support-elements, placed on edge, become soft and buckle, when water enters, and thus no longer prevent actuation of a valve loaded by a spring located below the bottle of compressed gas. The spring can be completely released, for the purpose of actuating the valve of the compressed-gas bottle, only when a locking element, projecting into a preloading device loaded by the spring, is removed. The locking element is firmly connected to a retainer in which the housing is secured. When the housing is withdrawn from the retainer, the preloading device is automatically unlocked, leaving the rescue-unit ready for automatic inflation of the floating element as soon as the water gains access to the support-elements.