The ocean is a vast and mysterious place, and humans have been exploring its depths for centuries. But how deep can a human dive with the right equipment? The answer depends on the type of certification a diver has, the type of dive they are doing, and the type of equipment they are using. The world record for the deepest open circuit dive is 332.35 m (1,090 ft). With basic open water certification, divers can explore depths of up to 18 m (60 ft).
With more training, divers can obtain advanced open water diving certification that allows them to dive to a depth of 30 m (100 ft). For recreational diving, the maximum depth is 130 ft. Appropriate certification is highly recommended for diving at those depths. As a basic open water diver, the depth limit for diving is 60 ft.
To dive deeper, advanced open water certification teaches divers about diving above 60 ft. For diving above 100 ft, the specialized deep diving course is highly recommended to learn how deep diving affects the body and how to properly prepare for an ascent from depth. Diving deeply can cause narcosis, which is like being intoxicated underwater. Although it is not dangerous in itself, if not recognized or corrected, nitrogen narcosis can cause an error in the diver.
The heliox mix can be used for dives of up to 300 m (984 ft), but if you want to go deeper, you'll have to replace the helium in the tank with hydrogen, as the helium will begin to have a narcotic effect. The depth at which you can dive will also depend on your personal air consumption and the number of tanks you use. Technical diving includes numerous tanks, including those found on the diver and those found on the ascent line. The world record for the deepest dive was set by an Egyptian, Ahmed Gabr, who completed his dive of more than 1,000 ft in the Red Sea and is considered to be the deepest dive in history.
Decompression sickness, air consumption and nitrogen narcosis are the main factors that influence how deep you can dive. With the right dive equipment, including a dry wetsuit, dive tank, gloves, etc., divers can reach depths of around 1000 ft or more. According to PADI (Professional Association of Dive Instructors), the estimated deepest depth that recreational divers can reach is about 130 ft, but their time to explore is very limited due to water pressure and compressed air becoming a threat to their health. They are designed for shallow diving and their main purpose is to increase the diver's decompression limit. For very deep dives, you need a special gas mixture to help you breathe comfortably and combat the effects of nitrogen narcosis when you dive.
As much as a human can dive at about 2000 ft (and that too with a special atmospheric suit), attempting a 12,000 ft dive is a mortal desire.