And we're off! The journey to reach 5,777 miles has begun, with two teams starting out from either end in Manchester and Madagascar.
We'll be tracking the progress below daily to see which team is ahead and how long is left to go.
As both teams race to meet in the middle, keep an eye on how close they are to meeting at the mid-way point near Mecca in the map below.
To learn more about the challenge, our MD Simon has written a blog on why we're doing this, our relationship with WaterAid and what to expect - read it here.
And don't forget, to help reach our fundraising goal head to our Access / WaterAid challenge Just Giving page where you can donate to a truly wonderful cause.