She wore her heart on the back of her bathers: "I love Alan Jones."

Adelaide great-grandmother, Margo Bates swam a metre of freestyle for every year of her life, bar one, at the Sydney Olympic pool on Thursday.

The 99-year-old dedicated her performance to Sydney radio broadcaster Alan Jones, who sponsored her to travel from South Australia to compete at the World Masters Games.

And it seems it was a good investment - Margo claimed her seventh gold medal for the games to add to a collection of 180 medals she's won over her entire life.

"I'm weighed down by gold," she told AAP. "I'm aiming for 200 medals. I'll be still swimming when I'm over 100."

Before the race, she'd said her strategy was to just keep swimming.

"I don't want to conk out," she said.

She said she'd been too busy partying in Sydney to bother training for the games.

"I had a night out last night on champagne and oysters," she said. "We did a harbour cruise."

Posing for photos with heat competitors Joan Godsall, 91, Joyce Faunce, 88, Rita Weberbauer, 85 and Val Lincon, 85, Margo said she felt like a teenager again.

Her son, Peter Jackson, was on hand to help his mother get into the water, along with a several swimming officials.

"We need a fork-lift," he joked.

Margo settled into a steady stroke for the first 50 metres, before having a bit of a breather at the other end of the pool.

"Once she gets going she has a better stroke than I have," one swimming official said.

On the final leg, Margo had another quick rest before finishing the last 20 metres to roaring cheers from the crowd.

Speaking on air to Jones after her swim, she thanked him for his generous support.

"My only regret is I haven't been able to meet you in person," she said.

"Oh, aren't you sweet," Jones replied. "At 99 years of age, you're brilliant, you are brilliant ... Margo, you're a star."

Jones promptly invited her to an Andre Rieu concert on Thursday night.

"You can come and see me tonight, I'm singing with Andre Rieu," he said. "So Margo, we're going to have a lovely night out with Andre ... don't wear that swimsuit."