The Unveiling: Discover the True Champion of Rivers in the Ultimate Expedition

In this CNN Travel series called Monthly Ticket, we highlight captivating subjects within the travel industry. This month, we are focusing on extraordinary aspects such as the largest, longest, and most expensive attractions and destinations worldwide.

In our current era, it is reasonable to believe that science has provided clear answers to some of the major inquiries about the natural world, particularly those tied to precise measurements. However, there is one seemingly uncomplicated question that remains perplexing: What exactly is the world's longest river?

In 2023, science is still struggling to find the answer.

Officially recognized by sources like Encyclopedia Britannica and Guinness World Records, Africa's Nile holds the title of "world's longest river." However, a forthcoming Amazon River expedition led by an international team of explorers and researchers is preparing to challenge this designation by traversing the river using rafts, horseback, and solar-paneled boats.

"The Nile compares to a worm while the Amazon resembles an anaconda," recalls Yuri Sanada, a 55-year-old Brazilian expedition leader, seasoned explorer, and film producer. He refers to his colleagues' metaphorical description of the Amazon's immense volume, which surpasses that of any other river by four times.

"Thus, there is no comparison – we possess the largest river. However, when it comes to length, only time will reveal the answer."

A 7,000-kilometer expedition

Brazilian expedition leader Yuri Sanada.

Aventuras Produções

The expedition, scheduled to begin in April 2024 and last for five months, intends to traverse the entire length of the Amazon. Utilizing advanced satellite technology for river mapping, the primary objective is to establish conclusive scientific evidence that the Amazon is not only the world's most voluminous river but also the longest one. It is important to note that the Amazon is not a single continuous body of water but rather part of an extensive river system that encompasses a significant portion of northern South America. Similar to branches on a tree, this interconnected network comprises numerous sources and tributaries.

The dispute over the length of the Amazon primarily arises from the disagreement on its starting point. Britannica and others traditionally measure the river's source as the headwaters of the Apurimac River in southern Peru. However, American neuroscientist-turned-river expeditionist James "Rocky" Contos, 51, claims to have discovered a more distant source - the Mantaro River in northern Peru - while researching whitewater rafting routes in the country.

"I knew that the Apurimac was considered the furthest source of the Amazon, but during my preparations for my trip to Peru, as I gathered all the information such as maps and hydrographs, I realized that there appeared to be another river that was longer," Contos explains.

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In order to authenticate the accuracy of this incredible claim, the individual undertook extensive measures. This included meticulous examination of topographic maps, satellite images, and precise GPS measurements, all conducted during his adventurous kayaking expedition on the river. The culmination of his findings were later shared with the public through a research publication in 2014.

According to him, the identification of the new source increases the length of the Amazon by 77 kilometers (48 miles) compared to the previously known source.

Sanada asserts that Contoss' discoveries provide a valid reason for the expedition team's presence. He explains that although mapping the river is the primary objective, the expedition also aims to extensively document and draw global attention to the remarkable biodiversity of the Amazon rainforest regions. Furthermore, it emphasizes the importance of international collaboration in conservation efforts.

The upcoming spring expedition will cover a distance of 7,000 kilometers (4,350 miles) as it follows the course of the Amazon River through Peru, Colombia, and Brazil. The journey will commence from the newly discovered source of the river at Mantaro, nestled deep in the Peruvian Andes.

The initial leg of the expedition will entail navigating the challenging whitewater of the Mantaro on a raft, led by Contos. Once the Mantaro merges with the Ene River, the main portion of the voyage will commence. It will involve three specially designed boats, powered by solar energy and pedal propulsion, to navigate the remaining stretch of the Amazon until it reaches the Atlantic Ocean on the Brazilian coast.

Sanada anticipates a secondary expedition to commence in early 2025, starting from the Apurimac River in Peru, which is widely recognized as the source of the Amazon River. This expedition aims to conduct a fresh round of measurements. Notably, French explorer Celine Cousteau, the granddaughter of renowned oceanographer Jacques Cousteau, will join the team and traverse the riverbanks on horseback.

Currently, Sanada leads a diverse team of approximately 50 collaborators from various parts of the Americas and Europe. The expedition has already established significant partnerships, including support from the Explorers Club, a deal with IMAX for a related film production, and an assignment to create a new map of the Amazon River for Harvard University.

Sanada announces that the expedition will welcome a diverse group of international scientific researchers from partner universities in Brazil, Peru, Colombia, the US, and other countries. These researchers will join the expedition at various stages, with the common goal of introducing sustainable technology to the indigenous communities of the Amazon region.

Some experts suggest Peru's Mantaro River, deep in the Andes, is the most distant Amazon source.

Jonathan Chancasana/Alamy Stock Photo

"These projects will provide valuable lessons on water treatment, eco-friendly house construction using natural materials, harnessing electric energy from renewable sources, waste management, sustainable transportation options like electromobility, and more," he elaborates. "This initiative has the potential to truly transform the lives of the people residing in the area."

The primary purpose of these hybrid solar- and pedal-powered expedition boats is to showcase a cost-effective, efficient, and environmentally-friendly alternative to the gas-powered motorboats that are presently utilized by the local communities.

Developed in collaboration with a Brazilian university, the vessels are being built using bioresin and natural fibers sourced locally, along with motors manufactured through 3D printing technology. After the expedition, the boat motors will be donated within the local community, representing a crucial aspect of the expedition's lasting impact.

Armed escorts and bullet-proof cabins

Despite these optimistic goals, embarking on this journey is not devoid of danger.

"In such expeditions, numerous pitfalls loom," Sanada explains, highlighting the risk of boat malfunctions and perils found in the wilderness (including jaguars, anacondas, poisonous frogs, and more).

According to Sanada, the "human interaction" is the most perilous aspect. He highlights the constant uncertainty faced by the team when encountering individuals in the wilderness – questioning whether they may be drug lords, adversaries, or simply a hospitable tribe inviting them for dinner.

As a precautionary measure, the expedition team is collaborating with local authorities to arrange armed escorts for their journey through regions notorious for illegal mining and drug trafficking. Additionally, the boat cabins are being equipped with fibers that are resistant to bullets and arrows.

Sanada feels that the risks are justified, as he has full confidence in his team. "I have enlisted the assistance of local guides hailing from the Amazon and Peru, individuals who possess extensive knowledge of the land and expertise in survival skills," he affirms.

"We cannot afford to halt (due to the risks involved). Our pursuit is driven by scientific endeavors, as we aspire to preserve this invaluable legacy for the Amazon," he declares.

He expresses a deep sense of privilege in being counted among a select group of merely around 10 intrepid explorers, and the very first South American, to have ventured on historical quests to traverse the entire length of these rivers.

Ultimately, though, Sanada admits that the expedition might not achieve a definitive answer regarding the length of the river or convincingly demonstrate its claim as the largest in the world.

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Dr. Suzanne Walther, an expert in river systems and measurements and an associate professor of environmental and ocean sciences at the University of San Diego, highlights the numerous challenges associated with measuring rivers. This is due to the dynamic and complex nature of waterways, as well as the potential for differing interpretations of accepted river sources and endpoints among different individuals.

Dr. Walther emphasizes that rivers can undergo various changes over time. These changes include differences in movement, varying water volumes, and fluctuations in seasonal patterns. As a result, even if you measure a river in the exact same way, the outcome can be influenced by its constant movement.

There is a certain level of uncertainty associated with every measure we undertake, whether it is due to tools, atmospheric interference, or the human element.

Additionally, she highlights the existence of a man-made incentive to lay claim to remarkable geographical features such as the longest river. This act not only fosters national pride but also has the potential to generate revenue from tourism.

"It gives prestige to a place," she says. "We place value on those things as humans, even if the rivers dont care if theyre longer or not."

A search for knowledge

After his Amazon expedition is complete, Sanada hopes to set his sights on the Nile.

Khaled Desouki/AFP/Getty Images

Whatever the expeditions outcome, Sanada says hed like to explore the Nile next, using the same techniques and methods of measurement.

The Nile, as it traverses northeastern Africa and flows into the Mediterranean Sea through Egypt, is a subject of contention regarding its origin. Multiple African nations make competing claims about being the source of the river's headwaters.

"Let's focus on surviving this first and then we can strategize for the next challenge," remarks Sanada.

Upon completion of the expeditions, a full-length documentary along with an IMAX film is anticipated to premiere in 2026. Sanada is confident that these projects will not only enhance regional pride and international tourism but also contribute to conservation efforts in the Amazon by showcasing its immense value and emphasizing the urgency to preserve it.

Ultimately, Sanada says that record or no record, "its all about a search for knowledge. Were going to be showing the world what the Amazon is all about."