Immersion Pulmonary Edema (IPE) is a relatively new form of hemodynamic pulmonary edema. The number of cases has been increasing over the last ten years and it has become the second most common cause of hospitalization for military divers, after decompression sickness. The pathophysiological mechanisms of IPE are not completely known. Its occurrence is linked to a combination of factors related to the environmental constraints of diving, as well as to the diver's equipment. The main external factors are increased hydrostatic pressure, cold, intense effort and emotional stress. The impact of internal factors is not known. At this time, no severe forms of IPE have been identified in the military. However, it is important to identify this pathology at an early stage, even if the signs appear minor, because the continuation of underwater activity can significantly worsen the clinical picture. The risk of recurrence (greater than 15%) could result in a severe or even lethal accident.