Yes, if they are made of polyester, nylon, or another synthetic substance. However, you should avoid wearing cotton boxers or underwear briefs. Boxers made of freeball, compression spandex, or synthetic material (polyester, nylon). Underwear briefs made of cotton will not only be uncomfortable but could also prove to be toxic if it gets wet. As long as you aren't swimming in a pool filled with chemicals that could damage your shoes, then you're good to go.