I'm VERY fair skinned but I love the beach.  I wore this (and another by a different manufacturer) for a week at the beach during the height of summer and had absolutely no burn.  The cost of this shirt was about $20 higher than the other brand I purchased and I must say it was worth the extra money.  I specifically appreciate the raised neck line which provided added protection.  My other shirt has a standard neck line (i.e. like a T-shirt) which tended to shift a bit in the ocean and was much looser on land.  Plus, the Coolibar just seems like a better quality shirt all around.  I'll certainly consider other Coolibar products in the future and I highly recommend their swim shirts.  Oh - and large was a perfect; I'm 6'2" and about 195 lb and sizing was exactly as expected.