How Deep Can a Human Dive Without Scuba Gear?

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Most swimmers and diving enthusiasts are eager to inquire how deep can a human dive without scuba gear. It’s a natural instinct to ask this question as you become more comfortable swimming under the water.

What most humans can achieve without training?

Let’s start by reviewing what PADI, Professional Association of Diving Instructors, suggest. According to the rules of the association, deep diving is described as a dive that exceeds 60 feet. It means that most of us without a scuba gear may safely dive a maximum of 60 feet without feeling the negative risks associated with diving beyond the limit.

For most swimmers, 20 feet is the maximum depth that they will free dive during their lifetime. For experienced divers, they can safely dive to a depth of 30 to 40 feet exploring coral reefs. Beyond 60 feet, your body may start to feel the negative physical effects associated with lack of oxygen and water pressure.

If we go by the definition of PADI, you can safely dive to 60 feet if you’re able to hold your breath for that long. However, it does not mean that anyone can dive to these depths on their first attempt. As a recreational swimmer, you should never dive without taking serious safety precautions because most swimmers diving without the oxygen are not aware of their limits to withstand water pressure at greater depths.

What humans have achieved?

human diving in blue sea water

While 60 feet may seem shallow or deep depending on your perspective, humans have been recorded to free dive at depth ten times greater than this without using scuba gear. It means that the human body is able to withstand immense pressure in a single breath of air.

The maximum depth reached by anyone in a single breath of air is 702 feet without any injury. The record was set in 2007 by Herbert Nitsch in a no-apnea limit competition. The same person also holds the record for the deepest dive without oxygen diving to a depth of 831 feet, but Herbert sustained brain injury on the ascent.

Due to an excellent rescue and medical backup plan, he was able to tell his story to the world. Had there been no one to help, Herbert would have sunk to the ocean floor. We will lightly touch on the incredible story of Herbert Nitsch later in this article as we try to answer the question.

Freediving record without any help

It should be noted that Herbert Nitsch was using specialized equipment such as high-speed diving sleds and inflatable balloons to help him dive that deep. Also known as no-limit apnea, the equipment helps a person to navigate such deep waters, safely.

There is also another class of free diving, constant weight apnea, which doesn’t use any specialized equipment. The record for such a dive is approximately 427 feet by Alexy Molchanov for men and 351 feet by Alessia Zecchini for women.

In both these free diving instances, swimmers were allowed to use fins to help them dive. In the competition, divers are allowed to use a single hold of the rope to stop the descent and start the ascent, again. It means that the diver can use the rope once, if they wish.

For most professional swimmers, the toughest form of free diving is known as constant weight without fins. It is the most challenging free dive without oxygen and as close to diving without any help or assistance. In this challenge, divers do not use fins to help them dive at greater depths. While they are allowed to use a single hold of the rope to stop the descent, many of the record-breaking swimmers may not use the rope even once.

The record for the dive is 335 feet is by William Trubridge of New Zealand. Similarly, Sayori Kinoshita of Japan holds the record for women at 236 feet.

Before these record-breaking attempts, Greek freediver, Stathis Hatzis, is known to have dived more than 200 feet on a regular basis without any assistance in search of the sponge. In 1913, he helped secure a line to the anchor of an Italian Battleship, Regina Margueritta as the anchor was stuck more than 285 feet below the water.

Based on these record-breaking attempts, you can get a general idea of how deep can a human dive without scuba gear.

How much depth the human body can endure?

woman diving in the sea and enjoying wild nature

Just a century earlier, it was thought that a swimmer cannot dive more than 300 feet before being crushed by the pressure of the water. As technology advanced, we understood that the human body can take a lot of pressure without adverse impact. In 1988, French commercial divers fixed an undersea pipe at depth of more than 1750 feet using sophisticated breathing equipment, but without any sort of special swimsuit. This is deeper than most skyscrapers and nearly as deep as Burj al Khalifa.

Will there be more records?

It seems that there will be more records set by individuals as the human body can adapt itself at immense depths due to its mammalian reflex. The mammalian reflex is the ability of the body to change itself according to its environment. When free diving, the human body goes through several changes helping it to acclimatize.

  • Bradycardia: To adapt to the cold water and lack of oxygen, the heartbeat can slow down by 10 to 25 percent. Experienced divers can reduce their heart rates to more than 50 percent.
  • Peripheral Vasoconstriction: To cope with the pressure, the body responds by shifting blood to the most important parts of the body allowing vital organs to function properly.
  • Blood Shift: Our lungs compensate from the excess pressure by expanding according to the changes in the human body.

The Story of Herbert Nitsch

While it’s true that the human body can adapt itself to the changes, there are inherent risks associated with deep dives. Getting back to the story of Herbert Nitsch, his ascent from the depth of 831 meters proved disastrous. At 100 meters below the surface, Herbert Nitsch blacked out due to a condition called narcosis.

He was rescued by the emergency divers. Before resurfacing, Herbert regained consciousness and descended 10 meters down the surface for 20 minutes to avoid the impact of decompression sickness.

The rehabilitation from the mental injuries took more than two months. During the recovery phase, he underwent rehabilitation to learn to walk, talk, and move around. According to Herbert Nitsch, the mood was so depressing that he tried to commit suicide by jumping from the second-floor window of the rehab center, only to realize that the window wasn’t that high.

What's the answer?

As you must have noticed that there is not a single answer to how deep can a human dive without scuba gear. The answer depends based on your perception of free diving and associated risks.

Still, these facts should provide us answers to the question. As of 2019, humans have known to reach depths of nearly 800 feet without using oxygen. Similarly, dives of nearly 400 feet are possible using fins. If you’re looking for the endurance of swimmers who do not use any kind of equipment, then William Trubridge has set the records at 335 feet.

The Greek free diver, Stathis Hatzis, is documented to reach depths of nearly 300 feet without any kind of outside help or safety precautions. Prior to Stathis, there is no official record of free divers; therefore, we can only assume that someone may have dived to even greater depths than Stathis as Stathis could only hold his breath for 3 to 4 minutes, maximum. Modern swimmers trained at holding their breath can hold their breadth nearly twice that time.

The jury is still out, but we know for certain that the human body is able to do amazing feats of endurance if properly trained.

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