I wore this on an excursion in Cozumel, Mexico and didn't get sunburned. I usually burn after 10 minutes outside unless I'm wearing strong sunscreen, and even with SPF 100 on I usually burn after about 30 minutes unless I reapply. I put SPF 100 on underneath this top, underneath some UV leggings, and a big sun hat and didn't get burned anywhere. My only complaint is that the top was one or two sizes too big in spite of the measurements working for me according to the chart. I excepted long arms and a long hem because I'm very short, but the chest and waist should've fit according to the size chart and they didn't. My bust is 30" and my waist is 24", I weigh around 90 pounds and am 4' 10". It wasn't so loose that it looked ridiculous, but it definitely didn't look like it fit. Also, when I cinched the hem up into the ruching the waist was so loose that it became almost like the leg of a bell-bottom jean. Instead of scrunching nicely like the product photo it came out on the sides like an awkward, stiff triangle. I wore it "dress style" the whole trip. It also didn't dry quickly at all. At first I thought that was because after swimming most of the excursion took place in a cave and under trees, but after hanging up to dry overnight it still wasn't dry the next morning. That being said, the seams look strong and the material is good quality, plus my most important goal was met- no sunburn!