The Dark Side of Tanning How to have your day in the sun without getting burned. It's impossible for divers to avoid all sunlight. Warming in the sun between dives is part of the fun of a tropical vacation. In fact, a little bit of sun is good for you.
Sunlight is necessary to make vitamin D, an essential vitamin.
The tanning process is actually your body's first line of defense against overexposure. When your skin is exposed to too much UV radiation, special pigment cells called melanocytes darken in an attempt to shield the skin from damage. The darker the cells get, the greater the damage your skin is suffering. Sunburn occurs when too much UV radiation overwhelms these defenses. The hours from 10 a.m. to 3 p.m., when the sun is highest in the sky, are when UV rays are strongest and cause the most damage.