Which method is NOT effective for preventing overexposure to the sun?

Ignoring hydration is not an effective method for preventing overexposure to the sun because it does not directly influence how the skin absorbs or reacts to sun exposure. Proper hydration is essential for overall health and skin integrity; however, it does not provide any protection against UV rays.

On the other hand, wearing dive skins, long clothing, and using sunscreen with an SPF of 15 or greater are all effective strategies for minimizing sun exposure. Dive skins provide a physical barrier against UV rays, long clothing also covers the skin to block sunlight, and sunscreen with an adequate SPF helps to filter harmful UV radiation. These methods create a protective layer, either through clothing or topical application, which is essential for reducing the risk of sunburn and long-term skin damage.