From Friday Pattern Company:
The Seabright Swimmer is a one piece swimsuit pattern that can be made with or without sleeves. It features a plunging neckline with gathering at the shoulder and waist. The instructions include a tutorial for adding a lace up neckline closure for added modesty. The sleeves let you look and feel glam while providing a bit of added sun protection!
You will need a fabric with 4 way stretch and at least 50% crosswise stretch. Keep in mind that your suit will be stretching both around your body and down it, so if your fabric doesn’t have 4 way stretch the it wont fit correctly. If you are making this as a swimsuit, you will need swim lycra. If you are making this as a body suit, any knit will do as long as it meets stretch requirements. You can use the same fabric for the outer fabric and lining or get separate lining fabric.