Aussie swim marathoner ready for illness

After swallowing heaps of Copacabana's polluted water, Australian marathon swimmer Chelsea Gubecka has said she doesn't care if she's sent to hospital because she's an Olympian.

The 17-year-old emerged from yesterday's rough and tumble women's open water marathon rapt with her 15th placing.

The Queensland university student was the youngest in the 26-strong field that contested the 10km race off Copacabana beach, won by Dutchwoman Sharon van Rouwendaal.

Gubecka was 16th across the line. But an unseemly grapple on the finish line between France's Aurelie Muller and Italian Rachel Bruni bumped the Australian up a spot.

The French and Italian swimmers were, quite literally, fighting for silver - Muller grappled her rival at the line, trying to dunk her.

She swam over the top of her but was disqualified post-race.

Australia's Gubecka reckons if she now gets sick, it's worth it.

"I have finished racing now so whatever happens, happens. If I end up in hospital - whatever," she said.

"I have raced at an Olympics and that is unreal."

The Australian gave as good as she got in a marathon where swimming becomes a contact sport - flying arms and elbows are routine.

"(It's) just unbelievable racing those girls and copping a few and getting them back. It's good fun," she said.

"I'm the youngest in the field by a fair bit, all these girls are nearly twice my age. So it's pretty cool, pretty special, to be a part of this and part of the Australian team."

Gubecka was on the pace when swimmers stopped for the first feed but then slipped as her experienced rivals accelerated.

"I held on for as long as I could and 15th, I'm pretty stoked," she said.

The surf-loving Gubecka started marathon swimming as a 14-year-old "little grom" and said she fluked an Australian title at her first attempt.

"They put me on the world championship team, that was my first little taste of international racing and it was very brutal," she said.

"Being 17 now and an Olympian, it's something you dream of ... I just happened to live it right now."