I've inherited most of my Irish Dad's genes and can get so white my friends have made believe I am invisible when we're out on kayaking trips.
So, quick product placement you might find helpful: last year I bought an LL Bean Cool Weave shirt and absolutely love it. While it has long sleeves, the material is super light and wicks moisture very well. If necessary you can roll the sleeves up comfortably and has a button to keep them in place. Excellent chest pocket with inner mesh and zip for quick stowing of sunglasses when jumping on a ride. Also, they are reported as UPF 50+.
I like collared shirts in the sun, since I find that I have the most trouble with the back of my neck getting too much sun when wearing t-shirts. I've worn these hiking in warm weather and I find they are much airier than most other shirts.
Not the cheapest shirt in the bin, by far, but I just noticed that some of the colors are on sale right now. I already bought a 2nd, now think I'm getting a 3rd for our upcoming trip! (Updated: I see the colors on sale are only in size Small. Blarg.)