In 2011, British adventurer Sarah Outen, 29, set off from under London’s Tower Bridge, taking her first push into what has become a five-year, 22,000-mile human-powered journey circling the Northern Hemisphere. Human powered—as in pedaling and rowing, using only her bike, kayak, boat, and feet to cover what will be nearly 26,000 miles all told.

It hasn’t all been easy going.

From intense weather far out at sea to a 1,500-mile diversion to the Aleutian Islands, anything can and will go wrong when you’re alone in extreme conditions. And she is almost always alone, traveling much of it without even a support vehicle. So far she’s about two years behind schedule, having just recently finished cycling 5,000 miles across Canada and the United States this winter.

Today, after a series of delays, she pushed off into the Atlantic from Chatham, Massachusetts, embarking on the final 3,200 miles home.

While there are those who argue that her journey isn’t technically a circumnavigation of the Earth—Guinness World Records defines that as crossing opposite points on the planet’s surface—she will be the first woman to accomplish the route she’s on, and it was never Outen’s intent to set a record. She is adamant that this is a journey she is doing for herself and to inspire others, as well as to raise money for an assortment of environmental and social charities.

We caught up with her on the docks in Chatham as she was packing equipment into Happy Socks, her specially designed boat.

What kind of conditions are you looking for to leave in?

I really need three days of clear weather with a westerly wind, not strong, and ideally behind that we don’t want a strong easterly wind. If there’s a strong easterly swell, it will make it hard for me to get away from land. It’s really just looking for a lack of wind.

How long do you anticipate this leg of the journey to take?

Three or four months.

And will you have a support vehicle with you while you’re out there?

No, it’s just me.

That must get really lonely.

Not lonely, I don’t think lonely is the word I’d use. Lonely to me is just sad because you’re alone. But it’s definitely isolating, that’s for sure.

Do you bring all your food and water?

I take food with me. That food then packs onto the boat, and then for water I have a desalination unit that turns sea water into fresh water for me.

Well, at least there’s no shortage of that!

Yeah, you just need the power to run it, and that can be a challenge itself.

Is that all solar-based?

I have solar and wind, actually. I’ve just had a wind turbine fitted for this journey.

What gave you the idea to do this? Why go around the world on just your own human power?

The idea came during another journey that I was making across the Indian Ocean. I rowed from Australia to Mauritius in 2009. I was four months at sea, and that was my first big journey, and that was really beautiful and empowering. Challenging, too, in many ways, but it gave me the idea, and the confidence to think, “Wow, there’s different ways of being, there’s different ways of chasing dreams, etc.” And being out at sea is interesting and exciting, and I knew I’d like to see more of that, and meet lots of new people, and so on. So that’s how it came to be, really. In search of adventure and wanting to share those stories as well.

And you have sponsors that pay for your equipment, right? You’ve said the boat was very expensive.

I have a lot of sponsors who I work with, but they don’t pay for the entire cost. A lot of my money has gone into it. Lucy, my fiancée, is renting out part of our house at home. I’ve taken out a bit of a loan as well.

What’s the hardest part about being alone for that long?

The ocean is going to be a really challenging place just to survive in and row in and make progress in. So looking after myself and the boat on a physical level. But then also keeping myself up. Keeping my spirits good on an emotional, psychological level. And being the only one that’s there to do that in person, that’s really exhausting, and that’s a lot of responsibility. Just keeping everything together, just keeping going in the face of lost of setbacks, which there will be with the weather, I think that, in its entirety, is the biggest challenge.

You’ve had some misadventures, such as capsizing and being stuck in the boat, and ultimately losing the boat. What’s the scariest thing that you’ve encountered?

I’ve capsized in the rowing boat lots of times. Just in the tropical storms of 2012 I capsized probably 20 times, and that was certainly a huge challenge just to survive that time. But then surviving the period afterward, when I came home and had to deal with the emotional and psychological fallout and trauma of that period, that was really difficult. And getting the journey started again after that, to go back out and have another go after I’d lost the boat, and to recoup finances to make it happen, rebuild the team, keep the sponsors excited, and get myself ready to go—that was really challenging.

What’s your diet like when you’re out there?

It’s a high-calorie, high-protein diet. About 4,000 calories a day. Lots of dried foods, dried fruit, nuts, jerky, granola, oatmeal, that kind of thing.

Do you catch fish as well?

I generally don’t, just because I tend to make friends with the fish, and I find it quite odd to eat something that I’ve been talking to for a few days.

That makes sense.

I might try this time, just because they taste so good. But I’d much rather say hello to the fish than eat them.

Have you seen any whales or sharks or anything?

Yep. The wildlife out in the ocean is my favorite thing about it.

What’s the most amazing thing you’ve seen?

Well, it’s hard to just pick one. But the shark that I saw in 2013 just hanging by the side of the boat as I was considering going for a swim was pretty special.

What kind of shark?

I don’t know. Somebody suggested it might be a blue shark.

This is the last leg of the trip?

When I get back to England I have to cycle, kayak, and row to get back to London. So I’m thinking of this as the penultimate trip, and then that final traverse will be the very final stage.

What do you miss the most when out there?

My fiancée, mostly.

Do you have communication with her?

I have a satellite phone, so I’m in touch with her most days, and I’m in touch with her over the email and text messages, etc. But it’s still really hard being apart for so long.

Anything you’d like to add?

Don’t be afraid of change. Embrace it, have a go, and put good energy back in the world.

You can follow along with Outen via her website.