Rashguards are a type of athletic shirt, named for the fact that it protects against rashes caused by abrasions. These shirts can be worn by themselves, or under a wetsuit and is used for light coverage in warm to extreme summer temperatures for several watersports including surfing, scuba diving, snorkeling, wakeboarding, body boarding, or simply for stand up paddle surfing or swimming. Rashguards are most often worn in surfing when the weather is too warm for a wetsuit and to prevent wax-based chafing from sliding on and off of a surfboard as a board's wax holds sand from the beach that could rub against your skin while paddling out to the break. Rashguards also offer some protection from the sun and are sometimes worn under wetsuits to prevent chafing.
For protection from the sun and elements, short sleeve rashguards are your best bet and SwimOutlet carries long sleeves from popular brands such as Body Glove, Roxy, and Volcom. Make a statement in bold prints and colors or choose a solid versatile top to outfit your body for a day on the shore.