[Minimalist75]

Originally Posted by Torchwatch

Naked skin has less drag in water than all natural fibres, so the swimmer must aspire to wear as little as possible in societies where naked swimmers in public pools was not acceptable.
The swim brief or slip was developed long before synthetic fibres such as nylon were developed.
Knitted wool swimsuits absorbed a lot of water and went very saggy when wet, your woolen slip might drag down to your knees. At school I once swam in the school pool in white PE shorts, they went completely see through and hid nothing from view, the weight of the wet fabric was more than the waist elastic could cope with so I had to hold them up with one hand ever when standing still in the water. At moments like this one wonders if it's easier to swim naked.
In the Olympics there was a runner named Orsippos, who won the short sprint in the 15th Olympics held in 720 B.C. Orsippos began the race wearing the traditional athletic garment -- a perizoma, a type of loincloth held up by a band of fabric that went around the athlete's waist. The story goes that it fell off Orsippos while he was running, and after his victory it was decreed that athletes should henceforth compete naked.
Nylon was available after World War 2 and Speedo in Australia made the first swim briefs from it that neither impeded the swimmer nor fell down.

A spin off of Cold War technology was coatings for submarines that allowed them to pass through the oceans without drag or noise. This technology was applied to polyurethane fabrics and turned into very low drag swimwear. Since Sharkskin fabrics had less drag in water than naked skin it made sense that the more skin you covered the faster you'd go. The regulations caught up with the technology and for racing swimmers PU jammers were permitted.
PU jammers have to be worn very tight and take time and effort to put on and take off, they are colosally expensive perhaps 10 time the price of speedos so can be worn only for racing and training.
Although they make Lycra jammers they seem to defeat the purpose for wearing jammers, having more drag than naked skin the fabric between thigh and knee serves no purpose but to slow you down. I've swum in some and they felt all wrong compared to swim briefs but they are ideal for wearing on a campsite and walking down to the beach in.
Many men reject Lycra briefs, square cuts and jammers because they want shorts with pockets for their keys, wallets and phones but you'd still have to empty your pockets before going for a swim, perhaps they go to the beach but never swim.

Full body PU swimsuits were permitted at one time. but regulations now limit them to waist to knees for men and shoulders to knees for women.