A young Yorkshire woman has begun a 1,448km (1,900 mile) swim from Lands End in order to reach John O'Groats.
Jasmine Harrison from Thirsk in North Yorkshire holds the title of youngest woman to solo row across the Atlantic.
The teacher, aged 22, will spend three months swimming along the west coast of Britain.
It's a first in the world. She said that no female has ever done it and she is raising money for charity.
Two other men, one man, had previously completed the swim.
Ms Harrison spoke to BBC Radio York just before she dived into the ocean.
She said, "I can only swim with tides, so I'll be swimming six-hours on, six-hours off for an entire day."
"As soon I get out the water, I'll drop my GPS point on the tracker to let us know where we need to go."
Ms Harrison stated that it was a difficult challenge, but she was only allowing herself to focus on the first 100 (160km) miles.
"The geography of the Cornish coast is so complex, there's no way to protect it."
"It's just the weather moving straight across the Atlantic so you just get battered, and there's no hiding place if you get hit by bad storms."
She said that other concerns she would have during the challenge include the shipping costs and unpredictable British weather.
She added, "What's happening in my mind will vary from day to day."
For added support, she will be accompanied on the water by a support boat and will have a kayaker nearby during the challenge.
She said, "It will be nice to have that," and not just the 40ft support sailing boat hovering above me all the time.
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