What began as skin protection activewear for surfers, rash guards in recent years have become general use, sun protection swimwear commonly called rashguards, rash guard tops, swim shirts, surf shirts, sun protection shirts, water shirts, or rashies.
Back in the day, surfers had three main concerns, other than sharks, while in the water. They needed to:
By using knitted polyester or nylon fabric with four-way stretch, activewear designers were able to make functional tops that met the goals of skin rash, stinging, and sunburn protection. Technological knitting advances have improved the wicking and UPF ratings of rash guard tops. Wicking is also known as the characteristic of textile to pull moisture from the skin to absorb and dry at the fabric surface. UPF is defined as Ultraviolet Protection Factor that is a certification rating of sun protection. You can find out more about sun protection ratings by clicking here.
For added wearability, seamstresses building rashies use a special flat-lock stitch sewing machine to provide flat seams that are much more comfortable to wear.
Nowadays, rash guards are made with a high percentage of polyester or nylon and smaller percentage of elastane, also known as spandex. The stretch of the fabric comes from the amount of spandex knitted into the fabric. The range of spandex can vary but typically makes up 10 to 20 percent of the knit. The result is a close-fitting or compression garment. In recent years, even loose-or-comfort-fit shirts have grown in popularity.
But what about female rash guards?
Over the years, activewear manufacturers have responded to the need for skin and sun protection tops designed with women in mind. With the awareness of potential skin cancer for active women who love the outdoors, it is of utmost importance that ladies choose beach, surf, and swim clothing that will protect their skin from harmful UVA and UVB rays.
Available in many attractive styles and colors, these rash guard tops, designed for use in or out of the water, come in long and short sleeve variations with many different styles.
Shirts:  Bust/Chest. Measure around largest part of chest with measuring tape around shoulder blades and under arms.  Sleeves. Bend elbow and measure from the center back neck, around the shoulder, past elbow, to the wrist. Note: All long sleeve shirts feature a button tab that allows it to double as a rolled-up short sleeve.  Neck. At the narrow-most part of the neck, measure around the circumference.
Pants:  Waist. Measure around the waistline with a loose tape. Round to the next size up. Note: All waistbands have elastic in the rear of pant that provides a flexible, comfortable fit.  Seat. Measured 8" below the top of the waistband.  Inseam (Voyager Pants). Measured from crotch to leg opening.  Rise. Measured from crotch to top of the rear waistband.
Headwear:  Measure circumference across the forehead (above brow) above the ears to the back. For all headwear, one size fits all from hat sizes:
6 1/2 (20.5" [or] 52cm) to 7 7/8 (24.625" [or] 63cm)
Select the size range that fits your actual measurements.
Headwear (Left) and Face Mask Tube (Right) Size Chart
Aqua Design | Men
Aqua Design | Women