Anhumas Abyss Incident: Tragic Cave Diving Accident in Bonito, Brazil

Anhumas Abyss Incident: Tragic Cave Diving Accident in Bonito, Brazil
Incident LocationDiver Names
Bonito, Brazil – Anhumas AbyssAlex Stewart, Zane Armstrong

Two friends went on a recreational dive in the Anhumas Abyss cave. They were excited as they rappelled 236 feet down into the cave to explore the blue waters of the Anhumas Abyss. However, something unexpected happened during their dive, leading to a tragic incident. Let’s delve into the details of this cave diving gone wrong.

The Location: Bonito, Brazil

The stunning cave known as the Anhumas Abyss is located in the serene small city of Bonito, nestled in the countryside of Brazil. Over the years, Bonito has transformed into one of the most significant and expansive eco-tourism hotspots in South America. To access the cave, visitors must navigate a narrow opening in the rock’s surface, as there are no established stairs for descent. The only means of entry is through vertical techniques like rappelling.

The Anhumas Abyss is an impressive natural wonder. It consists of a lake located approximately 262 feet deep, at the bottom of a 236-foot deep cave. This depth is equivalent to the height of a towering building with 26 floors. The descent into the cave lasts about five minutes. Once visitors reach the end of the rappelling experience, they find themselves standing on a floating deck built over the serene lake. The lake’s water boasts above-average visibility, allowing visitors to gaze in wonder at the speleothems, such as cones, stalactites, and stalagmites, that have formed over the years.

Scuba divers find the Anhumas Abyss to be a most exhilarating experience as they explore the underwater world of the lake. The lake inside the Anhumas Abyss cave is known for having an average water temperature of 18 degrees Celsius. It’s a place where the sun’s rays only penetrate the water surface for a brief time each day. Yet, the water teems with a vast array of marine life, including huge schools of fish.

Alex Stewart, a 24-year-old resident of New York, and his childhood friend Zane Armstrong, aged 25, both shared a passion for the outdoors and adventure. Alex had always had a profound love for the outdoors, engaging in activities such as snowboarding and mountain biking. When Alex visited Bonito, Brazil, he was captivated by the tales and pictures of the Anhumas Abyss. It quickly became a must-experience item on his bucket list.

Preparation for the Dive

In 2012, Alex and Zane embarked on their journey to become certified scuba divers. They dedicated their time and energy to completing numerous courses over the next nine months. Eventually, they achieved the coveted certification to dive up to 100 feet. Equipped with the necessary gear and training, they were ready to fulfill their long-awaited dream of exploring the Anhumas Abyss.

The Planned Dive

Alex’s aunt, Lucy, had planned a retirement party in Bonito, Brazil. Alex and Zane saw this as an opportunity not only to honor their aunt’s achievements but also to cross diving in the stunning Anhumas Abyss off their bucket list. They made reservations in advance, as daily visits to the abyss were limited to two groups of eight participants. Excited but committed to staying within their limits, they planned to limit their dive to a depth of 100 feet, well within the limits of their certification. After all, this was meant to be a recreational dive for them to enjoy.

The Tragic Incident

On Monday morning, Alex and Zane drove to the cave, filled with excitement to explore the Anhumas Abyss. They carefully went over their dive plan, ensuring they agreed on the depth they would reach. Around 8 A.M., they began their descent into the cave, rappelling down 24 stories through a tiny opening at the top. The descent was terrifying, but their efforts were rewarded with an incredible sight—the underground lake filled with sunlight, casting an amazing glow on the crystal-clear water.

As they explored deeper into the lake, they reached a depth of 100 feet. Zane, wearing a dive computer, signaled to Alex to stop. Alex indicated that he was okay, and when Zane motioned to start ascending, Alex agreed. However, before they could start ascending, they both stopped to watch as a school of fish circled them, momentarily distracting Alex. When the fish disappeared into the depths, Zane looked around for Alex and noticed that his friend had dropped below him, continuing to descend deeper into the water.

Descent into Darkness

Confused and concerned, Zane followed Alex down, aware that they were well past their limits and entering dangerous territory. Going deeper without proper training, specialized equipment, and gas mixtures posed significant risks. They were at risk of experiencing nitrogen narcosis and oxygen toxicity. Zane made the difficult decision to stop at 120 feet and swim for the surface, leaving Alex behind. Alex continued descending deeper and deeper until he was swallowed by the darkness.

In shock, Zane resurfaced and sought help from the local authorities. Two leading experts in rescue diving were deployed to the scene. After suiting up, they dived into the blue waters of the Anhumas Abyss and conducted several searches throughout the cave. Eventually, they located Alex’s body at a dangerous section of the cave, 213 feet deep, where visibility was significantly reduced due to massive sediments.

Due to the reduced visibility, the recovery operation had to be suspended temporarily. The risk of losing one’s way in such situations made the mission nearly impossible. After careful consideration, the recovery team decided to resume the operation the next day when visibility was expected to be clearer. True to their expectations, the visibility had improved, allowing the divers to locate and bring Alex’s body to the surface.

The Autopsy and Heart Condition Discovery

An autopsy conducted on Alex’s body revealed an underlying heart condition that no one was aware of. This discovery came as a shock to his family and close friends, including Zane. It served as a reminder of how fragile life can be and how little control we have over our fate. Despite the tragedy, there was some consolation in knowing that Alex had died doing what he loved most—exploring the depths of the ocean. His passion for adventure and living life to the fullest was a small comfort for those left behind.


The Abismo Anhumas Incident serves as a reminder of the importance of pursuing one’s passions and embracing life’s adventures. Though tragic, it highlights the risks involved in extreme activities such as cave diving. It is crucial to understand and respect the limitations set by certifications and training. Alex’s untimely demise is a sobering reminder to cherish every moment and approach adventure with caution.

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Where did the incident take place?

The incident took place in Bonito, Brazil, specifically in the Anhumas Abyss cave.

Who were the divers involved?

The divers involved were Alex Stewart and Zane Armstrong, childhood friends who shared a passion for outdoor adventures.

What was the planned depth of the dive?

The divers planned to limit their dive to a depth of 100 feet, well within the limits of their certification.

What happened during the dive?

While exploring the underwater lake, Alex unexpectedly continued descending deeper into the water, ignoring the agreed depth. Zane made the difficult decision to swim for the surface, leaving Alex behind.

What was the cause of Alex’s death?

Alex’s autopsy revealed an underlying heart condition that contributed to his tragic passing.

Rebecca Penrose
Rebecca, an experienced blogger, delves into the world of diving accidents, sharing insights, stories, and valuable lessons learned. Dive in and explore the depths of underwater safety.
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