Top: Hand of a day-laborer who had been drowned 24 hours prior
Bottom: Hand of a drowned person submerged in running water for several weeks
The process of tissues decomposing and sloughing off in animals generally reaches its peak around three to four weeks, in a moderate climate. However, in running water, the washing away of the acids from the liquefied fats and proteins, and the lack of insect activity, can often significantly retard or alter the decomposition.
Because of this, it can often take several extra weeks for tissues submerged in running water to separate from the body, and when they do separate, they don’t so much slough off when their substrate is consumed, but “slip” off, often in large sheets. The dermis of the hand is well-connected to itself, but less well-connected to its substrate, and as such is often subject to a phenomenon called “gloving” - where the skin slips off in, you guessed it, a “glove”.
Atlas of Legal Medicine. Dr. Eduard von Hofmann, 1898.