"There is one planet, and if we don't share it wisely, we will lose it." That's what Iranian-born Dutch adventurer Ebrahim Hemmatnia said in 2014, before beginning a pedal-powered trip around the world. While his intention is to draw attention to how interconnected we all are, it's his unique mode of transport that's really turning heads. Named Melanie, the four-wheeled propeller-equipped vehicle can be pedalled on both land and water. Amazingly, he's already used it to cross the Atlantic Ocean – setting the Guinness Record for "Longest journey by amphibious bicycle" in the process.

Melanie's buoyant body is composed of a marine-grade foam core covered with a carbon fiber skin, and is 6 meters long by 1.4 m wide (19.7 x 4.6 ft). That length includes the cockpit and sleeping cabin, along with storage space for food, a sea water desalinator and other essential equipment. It's sort of like an amphibious version of WiTHiN, a pedal-powered boat that was designed to go from Canada to Hawaii.

In "land" mode, Melanie is carried along by four fatbike wheels, the rear two powered by Hemmatnia's pedalling. When it's time to enter the water, the wheels are removed, and a clutch mechanism switches the drivetrain over to spinning the propeller. Solar panels on the deck are then used to power onboard items such as the desalinator, navigation lights, and satellite phone.

Additionally, some of the pedalling power can be diverted to a generator. This charges up a battery, which in turn powers a small motor. As a result, Ebrahim can take breaks from pedalling without losing propulsion.

After a period of preparation that included pedalling across the North Sea, Hemmatnia's "World With No Borders" expedition officially began on Nov. 22, 2014, when he set out from Dakar, Senegal. He proceeded to pedal across the Atlantic Ocean with no support vessels accompanying him, reaching the city of Sao Paolo, Brazil some 68 days later. Although the vast majority of the 2,371-km (1,473-mile) journey was spent at sea, he did also have to pedal about 70 km (43 miles) from the Brazilian coast to the city of Sao Paolo itself.

He has since returned to The Netherlands, to raise funds for the remainder of the expedition by selling a recently-completed book – The Oceanbiker – that details his Atlantic Crossing. Once the trip recommences, he should be following a route close to the Equator, taking him through points such as Tahiti, Australia and Kenya, before arriving back in Dakar.

All told, it will be around 50,000 km (31,068 miles) and may take up to five years. For Ebrahim, though, it will all be worth it if it helps to encourage the free exchange of knowledge and ideas between countries and cultures.

"Borders were created by human minds, they can be removed by human minds," he says. "There is no need for borders, we are all human beings."

View gallery - 9 images