Drowning damage is only incurred while the player is moving, standing still in water does not cause drowning wounds.
Drowning wounds are untreatable, but they heal very quickly and never get worsealways disappear after a brief rest on land, regardless of [[Wounds|wound severity]]. Note that drowning wounds do not heal while in the water, and bad/severe wounds will get worse over time if you are stuck in the water.
Currently, drowning damage is listed as fire damage. This will probably change in the future.