While the film, titled 10, has been to some extent forgotten in the annals of pop culture history, that scene was not. Derek's celebrity never seemed to wane, though her career has had its ups and downs. Now she is staging the mother of all comebacks with a role in the "schlockbuster" Sharknado 3: Oh, Hell No.

And the role, the 58-year-old actress-turned-environmentalist says, came with an unusual and unexpected endorsement.

"I haven't worked in a long time, I was in the Galapagos Islands with a group of conservationists and we'd been working on shark-finning for a long time," Derek says. "I said, you'll never guess, I just got a call for this movie, Sharknado. And they all said, oh, we love Sharknado. I thought they'd say, don't do it, it's terrible for our cause, [but] they said, do it, it's fantastic. So I did it."

Derek will star in the film as May Wexler, the mother of Tara Reid's character, April Wexler. Derek's on-screen husband Gil will be played by former Baywatch star David Hasselhoff.

The pair are not the only new addition to the film: other celebrities making appearances include Dallas Mavericks owner Mark Cuban, talk show host Jerry Springer, author Jackie Collins, Today show hosts Matt Lauer and Savannah Guthrie and singer/songwriter Michael Bolton.

The third Sharknado film, much like the first two, largely follows Fin Shephard (Ian Ziering) and April Wexler (Reid), as they make a stand between humanity and an invasion of tornado-propelled sharks. Its bad special effects and paper-thin plot, in particular, seem to please the franchise's massive audience.

In the aquatic pseudo-horror genre, however, this it isn't Derek's first rodeo. In 1977, two years before she starred in 10, Derek had a role in Orca, an awkward attempt to do with whales what Jaws had done with sharks.

"When the director called, I said, you know you're talking to an Orca star," she recalls, laughing. And on signing up for Sharknado? "It's fun to be part of something that's so young, such a phenomenon."

Perhaps the most striking thing about meeting the 58-year-old Derek is that she has changed so little. Older, yes, and dressed with a sharper sense of her own style, but still every bit as luminous as she was in 1979, jogging on that beach.

We are sitting in the Grimaldi Forum, a labyrinthine complex of corridors and meeting spaces perched on the waterfront in the tiny European principality of Monaco. Derek is here as a juror for the Monte Carlo Television Festival, though her upcoming role in Sharknado, and her fame from 10, have stalked her all the way to the French Riviera.

Few celebrities, even the most famous, have to contend with comparison to a single image. For Derek, the corn-braided, beach jogger Jenny Hanley in 10 has become something of an inescapable touchstone, though the comparison does not bother her.

"I feel a lot older, because I am a lot older, but I look back and see that that was the beginning of a magical life, and it wasn't expected," Derek says. "The part I played was very small, I'm only in the movie about ten minutes. To become [famous] from a very small part was completely unexpected."

She wasn't prepared for fame then, she says. And neither was the studio, not realising her small role would become the film's most impactful element.

"I didn't have a PR man, I didn't have representation, I didn't have an agent, it just happened overnight," Derek recalls. "For me, it was difficult. Some people thrive on the attention. I didn't. For me, my sanity came from my other interests."

And fame, even then, she recalls, was "very intrusive. Because there wasn't even a bio available for the press, it forced them to create one. The editors said, go get something on this girl and there was nothing. The compliments were extreme, the criticisms were extreme, it was very difficult."

In 2015, the older, wiser Bo Derek has a bit more on her plate. She is developing a television series titled Capitol Crimes, based on a series of novels by Warren Adler, with Boardwalk Empire's Eric Overmyer. And she is planning to gently re-start her acting career.

"I finally graduated to where no one asks me to be in a bikini anymore," she says, laughing. "That's nice. So that will automatically change the kinds of parts I get: bikini not required."

As film legend Bette Davis once said, old age ain't no place for sissies. It is a sentiment with which Derek agrees. "Forgetting the obligation to look a certain way, even though you're too old to look like that anymore, the aches, the pains, physically what you go through when you get older," she says.

Since 2002 she has been in a relationship with former Sex and the City and My Big Fat Greek Wedding actor John Corbett. Aside from her long marriage to photographer John Derek, it is only the second significant relationship in her life.

"I am unusual in Hollywood for staying," she says, reflecting on that point. "When I find a relationship, obviously, I stick like glue. I enjoy my privacy now, I really do. I still get to come here and do fun things, and be part of the business, but that intensity that I had, I'm glad that's gone. I don't mind that at all."

Her life, she says, is simpler now. Away from Hollywood, her great passion is breeding Andalusian horses, and she is an advocate for animal rights.

"Horses are much more sensitive, and they're not a predator," she says. "Our pets tend to be predators like us, so we automatically communicate. [With] horses, it's much more difficult, because you're prey. So you have to be much more subtle and gentle with them. They're more of a mirror reflecting you back."

Sharknado 3: Oh, Hell No! airs Thursday, 9.30pm on the SyFy channel.