UV radiation under water
It is a big mistake when we say water protects from UV radiation. Clear water is - just the opposite - very permeable for solar UV radiation.
How deep it impacts in the skin depends on the length of waves and radiation. The literature talks about numbers of 310 nm by 8 cm up to 20 cm.
Most of the measures resulted much bigger deeps for the UV-A section - up to 100 meters!
When we now know that water is moistening the skin and therefore the UV radiation is able to impact deeper in the skin we now know that we have to protect more in water.
