Oedema aquosum is seen in the following condition:

If the victim is unconscious at the time of drowning, mere flooding of the lungs with water, but without formation of columns of froth occurs, which is known as oedema aquosum. Also know: Drowning fluid actually penetrates alveolar walls to enter the tissues and the blood vessels. This has been described as emphysema aquasum. It is the presumptive evidence of death from drowning. Ref: The Essentials of Forensic Medicine and Toxicology by Narayan Reddy, 27th edition, Page 326-327.