If your boy is irresistibly drawn to any body of water within a mile, better dress him in The North Face Boys' Circle Gets The Logo T-Shirt instead of a cotton tee. Splashes, dunks, and spills are of less consequence when he's wearing this quick-drying shirt; it also wicks efficiently if he's generating his own moisture. The soft, comfortable pill-resistant fabric also offers UPF 50 protection for his frequently-burned shoulders.
My son asked for a "Biking" t-shirt. I thought that this was a performance t-shirt, but the fabric was not quite what we had in mind. We returned it for a Pearlazumi shirt which was more of a traditional biking fabric.