How Do You Tan in Water?

Tanning in water occurs primarily because the water reflects and allows the penetration of ultraviolet A (UVA) rays, which are the main cause of skin tanning.

The Science Behind Tanning in Water

While it might seem counterintuitive, being in or near water can actually intensify your sun exposure, leading to a quicker tan—or sunburn. Water does not block UV rays; instead, it interacts with them in specific ways that affect your skin.

As Dr. Punjabi stated, "The water reflects the UVA, which causes tanning, and the UVB rays that are responsible for burning of the skin. UVA rays penetrate below the surface of water as well.” This means that even when partially or fully submerged, your skin is still exposed to the tanning rays.

• UVA Rays: These rays are primarily responsible for stimulating melanin production, which leads to tanning. They can penetrate deeper into the skin layers and, as noted, also penetrate the water's surface.
• UVB Rays: These are the main cause of sunburn and contribute to skin damage. While water reflects these rays, they are still a significant concern.

Why Water Can Enhance Your Tan (and Risk)

The unique properties of water contribute to how you tan while in it:

• Reflection: Water acts like a mirror, bouncing UV rays from the sun and sky back onto your skin. This means you're not just exposed to direct sunlight, but also reflected sunlight from below and around you, potentially increasing your overall UV exposure.
• Penetration: As mentioned, UVA rays can penetrate several feet below the surface of clear water. This allows for tanning even when you're swimming or diving just below the surface.
• Cooling Effect: The cooling sensation of water can make you less aware of the intensity of the sun's rays. This can lead to staying in the sun for longer periods without realizing the extent of your UV exposure, increasing the risk of over-tanning or sunburn.

Practical Tips for Tanning Safely in Water

While water can enhance your tan, it also increases your risk of sun damage. Always prioritize skin protection:

1. Apply Waterproof Sunscreen: Use a broad-spectrum, water-resistant sunscreen with an SPF of 30 or higher. Apply it generously at least 15-20 minutes before entering the water and reapply every two hours, or immediately after swimming or excessive sweating.
2. Limit Exposure Time: Even with sunscreen, prolonged sun exposure can be harmful. Take breaks from direct sunlight, especially between 10 AM and 4 PM when UV rays are strongest.
3. Seek Shade: Utilize umbrellas, hats, or shaded areas when not actively swimming.
4. Stay Hydrated: Drink plenty of water to prevent dehydration, which can be exacerbated by sun exposure.
5. Monitor Your Skin: Pay attention to how your skin feels. If you start to feel warm or notice any redness, it's time to get out of the sun.