I suspect the material of the punishing implement would play a part. I believe that a leather strap or paddle used on a wet bottom tends to 'stick' slightly, transmitting force more efficiently to the area of impact.
The type of material the shorts are made of could also make a difference - water would make thin material stick to the skin of the bottom, making it effectively skintight with no cushion of air between cloth and flesh, but heavier material, or multiple layers, might absorb enough water to act as padding.
The other factor that might affect the development and duration of marks would be that wet clothing could act as a cold compress applied to the bottom, reducing bruising.
This is one of many areas that would benefit from research (which I would, of course, be happy to carry out, given adequate funding and a supply of suitable experimental subjects). |