I have been surfing nearly 20 years and have consequently worn 20 years’ worth of rash guards. These are absolutely the best It is multifunctional, serving as a great rash guard while completely protecting me from those UV rays we now know to be so harmful. During the cold winter months, it also works well under a wet suit, providing further insulation and warmth. Strongly recommended for anybody who surfs, dives, or just hangs out in the sun.