The only two photos that are real, other than the obvious porn photos: one really old one that shows a group of naked swimmers on the side of the pool/sitting in the bleachers, and the one showing naked swimmers in the pool holding onto the side while kicking their feet, who by the way are in military training. I do not know the origin of the first one, but the second one is from LIFE magazine. LIFE has also published photos of Michigan State University swim team members swimming nude during practice, but not at meets, and one of a junior high school swim class playing water volley ball nude. In that issue I think they actually mention that they boys swim nude.Images # 2 and #5 look very much like naked boys and clothed females. Are these photoshopped?
All the other ones on that site are fake. I have seen the originals of most of them and have them in my collection of 30,000+ digital photos.
By the way, there is a photo curculating of two swimmers posing on a diving board that is also photoshopped. I have the original with swimsuits on.