Being underwater provides some degree of protection against UVA and UVB radiation, but it is not completely effective. The extent of protection depends on various factors, including water depth, clarity, and the presence of additional protective measures.
Water can act as a natural sunscreen by absorbing or scattering UV radiation to some extent. The surface of the water, where most people spend their time, can block or reflect a portion of the UVB rays, which are the primary cause of sunburn and skin damage. However, UVA rays, which penetrate deeper into the skin and contribute to long-term skin damage, can still pass through the water to some degree.
The level of protection also varies with water depth. Shallow water provides less shielding from UV rays compared to deeper water. For example, in shallow water, such as a swimming pool or a beach with clear water, the protection may be limited, especially if the water is calm and there is no shade. In contrast, in deeper water or in environments with more turbid or murky water, UV penetration is reduced, providing a somewhat higher level of protection.
It's important to note that being underwater does not provide complete protection from harmful UV radiation. It is still crucial to take precautions when exposed to the sun, even when underwater. Wearing appropriate sun-protective clothing, such as rash guards or wetsuits with UPF (Ultraviolet Protection Factor) ratings, and applying waterproof sunscreen on exposed skin can enhance the level of protection against UV radiation while swimming or diving.