When carrying out a water emergency rescue, to rescue, particularly from a helicopter, a plurality of victims in a wide area of water without any drowning occurring. [Solution] A water rescue device is formed from: a hollow tube-shaped air chamber which is stored in an evacuated state; a gas injection mechanism which injects a pressurized gas in the air chamber; a pressurized gas tank which retains the pressurized gas; and a case which houses the air chamber, the gas injection mechanism, and the pressurized gas tank. When the case is lowered upon a water surface from a helicopter, the pressurized gas in the pressurized gas tank is injected via the gas injection mechanism into the air chamber, and the air chamber is released from the case, expanded in a swirl shape, and deployed on the water surface.