This year, I grabbed 21 sunscreens of various types and tested them. I have very fair skin (ghostlike, my family says) and burn easily. I tried the sunscreens while gardening, while going for a long hike in the middle of Austin in the heat of the day (don’t try this at home) and while swimming at the pool.
I also rotated which area of the body each one covered to make sure that each sunscreen got an opportunity to be on both the upper body and lower body, except the ones that were made especially for the face. I tried ones that sprayed on, foamed on, slathered on and apply like deodorant. Some were all natural, some had chemicals by the dozen; some were sunblock rather than sunscreen. They had SPF (sun protection factor) of 21 to 100. Was there a difference?
The good news: All of them were better than nothing at all. The patches of skin left bare definitely reddened.