This is the swimwear I wear, http://www.coolibar.com/women-s-swimwear.html
Yeah, it's not fashionable but it saves me from burning. I think this is what they are talking about when they say UV protectant swimwear, not a t-back or something. I can't understand wearing UV protectant clothing, it would seem that normal clothing if it isn't wet wouldn't be a problem.
As for t-shirts, they're ok, but I find them to be positively gross feeling when they get wet. The swim shirts are silky and dry fast. I guess it's all about whether you burn or not, no lie, I got burned this week just talking to my neighbor when I went out to get the mail. We talked for maybe 15 minutes and I came in red.