I have a TYR rashguard that I believe offers UPF protection. I bought it for snorkeling in Hawaii to add some sun protection. I find it fairly comfortable and it actually helps cool me if it's wet from swimming. I found that anything with a zipper was very uncomfortable, so I would avoid those.

My husband has really taken to wearing swim sun shirts as well as hiking / fishing sun shirts and seems to find them very cooling and comfortable. I think they make them very breathable.

Last year during their end of season sale I picked up a couple of suits from Old Navy online. They are two piece: bottoms and a long sleeved zip front top. The top is plenty long enough to meet the bottoms so no skin showing— on me, anyway. One set is black and the other is orange and hot pink. They were inexpensive, fit well and protect from the sun.

I also have four or fove shirts for golf that are sun protective from a company called N’vo

I take a water aerobics class in an outdoor pool 2-3 times a week year round. I wear a tank style bathing suit with a lightweight long sleeve zippered rash guard over it. It does a great job of keeping the sun off my shoulders and arms. It was cheap and it's lasted over a year without fading or ripping. Comes in a bunch of colors. From Azon.

Grr, wrote a nice long response and it disappeared. Ill try again later.

I’ve had good luck with UV swimsuits from Rodasoleil. They’re comfortable for sitting on the beach, and I like that they give more coverage without feeling like a heavy coverup. For me, the biggest plus is not having to constantly worry about my shoulders and arms burning, especially on days when I’m mostly just sitting out rather than swimming.

I’d look for something with long sleeves and a simple neckline, and personally I’d avoid anything with a stiff zipper if you’re planning to lounge in it for a while. A two-piece set or a swim dress/rash guard style can be a good compromise if you want sun protection but still want it to feel like beachwear rather than athletic gear.