“Did you know the average cotton t-shirt has an SPF equivalent of 5?” That message greeted me on the website of Cabana Life when I logged on to figure out if I really needed to be one of those moms ...

What we’ll refer to—for simplicity’s sake—as the “cabana” shirt goes by many other names, notably “camp” or “Cuban.” Whatever moniker it’s attached to, the instantly recognizable style can be ...