McCardel eyes 200km-plus swim

Let's play a numbers game.

You've just spent one night in hospital after swimming 126km in 42 hours.

And now you want to try swimming that distance all over again, plus an extra 75km.

For most of us, it just wouldn't add up.

But Chloe McCardel isn't most of us - she's a 29-year-old marathon swimmer who has just completed a gruelling swim in the Bahamas.

While it's yet to be officially recognised, the feat is being reported as the longest open-water, solo, continuous marathon swim in history.

But the likely entry into the record books has cost her.

McCardel is bedridden in the capital of Nassau after stumbling ashore early on Wednesday morning, local time.

She's suffering from the effects of more than a dozen jellyfish stings and is on a course of pain medication.

Her arms and legs are covered with welts and her eyes are encircled by blisters from her goggles rubbing against her skin.

"Every time I put my head in the water it was pitch-black," McCardel said.

"I couldn't see anything."

"You just hope with every arm stroke that you're not going to hit something."

It sounds like a nightmare.

Naturally, McCardel can't wait to do it all again.

She says she's planning something "pretty big" for her next trick, to take place within the next two years.

"It's going to be completely on a whole other level," McCardel told AAP.

"(It'll be) longer than 200km."

In the meantime, though, the Melburnian is focusing on a more immediate goal: walking again.

So why does she, in her words, "risk life and limb" with such extreme endeavours?

"I ask myself that question. It's very sadistic," she laughed.

"Right now I'm not walking. But you know, I'm someone who has big dreams."