Rash Guards have evolved from the old days of tight fitting, no stretch, andno breathability into a whole new world. The AKONA considers them Sun Shirtstoday. What s the difference? The Sun Shirts today are made with much lighterweight materials, with more stretch and flex, and have significantly morebreathability. In short, they are so much more comfortable, they can be usedfor any water sport of you choosing or just sitting in sun all day long at thebeach or on a boat.