Blue Peter presenter Helen Skelton has started her biggest challenge ever - kayaking solo down the Amazon River.
She'll be paddling an incredible 2,010 miles, and if she succeeds, she'll be the first woman in history to kayak down the Amazon on her own.
Helen will have to paddle 60 miles a day for the Sport Relief challenge.
"People say it can't be done, but worrying about it won't make it any easier or the distance any shorter," Helen said before she left.
"A couple of months ago I'd only sat in a kayak once.
"It's a massive challenge but I'm hoping that if people see I am out of my comfort zone they'll be more likely to challenge themselves and get involved with Sport Relief," she added.
Helen's doing the challenge for Sport Relief
Helen will be battling all sorts of beasties on her adventure, including piranhas, electric eels, sting-rays and anacondas.
She's also bound to have blisters and back ache from rowing.
Although other people have claimed to kayak further in the past, Helen will become the official Guinness World Record holder for the longest solo journey by kayak, if she finishes her challenge.
Helen started her journey on 20 January near a place called Nauta in Peru, and is due to finish six weeks later in Almerim in Brazil.