To celebrate summer, we’re asking the season’s most iconic superstars to share their warm-weather secrets. Here, former actress and model Bo Derek makes a case for the one-piece swimsuit.

There’s something so timeless, almost mysterious, about a simple nude one-piece. Sometimes being covered up is more suggestive. I think if my character in [the 1979 film] 10, Jenny, had worn a red or black bikini it would have felt too contemporary to create that sense of fantasy.

VIDEO: The Evolution of the Swimsuit

She was supposed to look like some kind of goddess, although in the end it turns out she was a liberated, modern woman and not what Dudley Moore’s character, who was obsessed with her, had expected at all.

Dos Gardenias swimsuit, $242; dosgardenias.com.

The style above reminds me of the lovely scoop-neck suit I wore throughout the movie. We actually used two different suits for the part: The first—which I think was by Cole or Jantzen, two big swim labels at the time—was lost in production before we shot the scene where I run on the beach, so we had to replace it with a leotard that looked similar. It was a little more sheer and skimpy, but you do what you have to do, and no one has noticed in all these years!

Maillots were all the rage back then, but when I check Instagram now, a lot of women still post cute vacation photos of the same look. I think it’s because the understated color is classic and the perfect way to show off your figure.

For more stories like this, pick up the July issue of InStyle, available on newsstands, on Amazon, and for digital download now.