One-and-done Billabong swimsuit in a retro-inspired one-piece style. Features a plunging sweetheart neckline, demi underwire cups and adjustable tank straps. Finished with a high-cut leg and cheeky coverage. An icon in the surf industry for decades, Australian brand Billabong got its start when founder Gordon Merchant started producing board shorts by hand in 1973. Now, they maintain a prominent presence among surfers, while also creating swimwear that looks just as good lounging on the beach as it does riding the waves.