A 64-year-old patient came to the Emergency department because of dyspnea which occurred during diving in a lake. After analysis, it was concluded that it was caused by immersion pulmonary edema. This is believed to occur due to the water pressure, which leads to higher central blood volumes and thereby higher cardiac and pulmonary blood pressures, which lead to extravasation of fluid. After diuretics and oxygen supply, the patient was fully recovered.