Referred to by a variety of names, depending on which part of the world you are from, there are a few distinguishing features but, most simply, the rash guard is tight fitting and a sun or swim shirt is looser fitting. At Surlaplage we have the ‘rash shirt’, which is designed to be slim fitting.Click to see full answer. Also to know is, what is a rash guard shirt for swimming?A rash guard, also known as rash vest or rashie, is an athletic shirt made of spandex and nylon or polyester. The name rash guard reflects the fact that the shirt protects the wearer against rashes caused by abrasion, or by sunburn from extended exposure to the sun.Beside above, can you wear a rash guard in the pool? Unlike cotton T-shirts, rash guards are fine for swimming pools. An old tee can harbor bacteria, requiring the use of more chemicals to keep the pool safe and hygienic. Cotton also breaks down in chlorinated water, and loose fibers that wash away can clog a filtration system. Secondly, is a rash guard the same as a swim shirt? Swim shirts and rash guards can be very similar, or very different. Some rash guards are constructed from super-strong materials that help athletes avoid skin injuries, while others are made from simpler fabric that provides extra warmth and prevents sunburns – much like a basic swim shirt.Can you wear a rash guard as a shirt?For the uninitiated, a rash guard is the neoprene “shirt” surfers wear to protect their skin from sunburn, scrapes, and other hazards of the trade, and now it is possibly also coming to an outfit near you. A Shopbop rep told us they envision the garment as a regular part of your daily wardrobe.