Before 20th century there was no concept of beach wear. People used to bath naked. Some of the Roman murals depict women playing sports wearing two piece clothes. One piece covered their breasts and the other covered their pubic area. There is no such evidence that may claim that there was any special kind of dress wore for swimming during this time.
As stated above, the two piece clothes, may be termed as, in today’s time as Bikini. It was Marilyn Monroe that gave the garment the push that it needed to be what it is today. Beach wear these days is available in different types. For ladies, you may opt for a Bikini to a single piece swimsuit. Both ways you may cover your body with a scarf or a poncho while not inside the water.
For wearing a bikini, having the right bikini body is a must, else you may make fun of your own self. There are many more options like for instance if you are a lover of Mother Nature, then you may opt for something that is eco-friendly. Sarongs are good options if you are not comfortable in just your bikini or single piece swimwear. A simple solid color shrug may make you feel good too. After all, comfort is of prime concern.