Can Ocean Pressure Crush You?

While the immense pressure in the deep ocean is certainly dangerous, the answer to whether it crushes your body in the way you might imagine is more nuanced.

No, ocean pressure itself does not typically "crush" the solid and liquid parts of your body because they are mostly incompressible.

However, the pressure poses a severe threat by collapsing the air-filled spaces within your body.

Understanding Ocean Pressure

Water pressure increases dramatically with depth. For every 10 meters (about 33 feet) you descend in the ocean, the pressure increases by approximately one atmosphere (the pressure at sea level). This means that at significant depths, the pressure is hundreds or even thousands of times greater than what you experience on land.

• Surface: 1 atmosphere
• 10 meters: 2 atmospheres
• 100 meters: 11 atmospheres
• Mariana Trench (deepest part): Over 1,000 atmospheres

Why Your Body Isn't "Crushed"

As referenced: it is not the pressure that would crush you, but the air in your lungs and other air-filled spaces in your body.

• Incompressibility: The majority of the human body is composed of water and other tissues that are largely incompressible under pressure. Similar to how a water balloon doesn't shrink significantly when squeezed underwater, the solid and liquid components of your body resist compression.
• Air Spaces: The vulnerability lies in the areas filled with air, such as your lungs, sinuses, ear canals, and intestines. These spaces are highly compressible.

The Real Danger: Compression of Air Spaces

When exposed to high pressure, the air in these cavities is compressed according to physical laws like Boyle's Law, which states that pressure and volume are inversely proportional (as pressure increases, volume decreases).

Effects of Pressure on Air Spaces:

• Lungs: Without specialized equipment like scuba gear supplying air at ambient pressure, the air in your lungs would be compressed to a tiny fraction of its original volume at depth. This can lead to lung collapse.
• Ears and Sinuses: The pressure difference between the external water pressure and the air pressure in these cavities can cause extreme pain, rupture eardrums, and damage sinuses (known as barotrauma or "squeeze").
• Other Cavities: Air trapped in fillings, gear, or even the gut can also cause issues due to compression or expansion upon ascent.

Beyond Compression: Decompression Sickness

Another significant danger when returning to the surface after diving at pressure (especially with scuba gear) is decompression sickness, commonly known as "the bends." This occurs when gases (like nitrogen) absorbed into the body's tissues under pressure form bubbles as the pressure decreases during ascent. These bubbles can block blood vessels and damage tissues.

How Divers Manage Pressure

Professional divers and submariners use technology and procedures to manage these pressure challenges:

• Submarines/Submersibles: Maintain internal pressure close to surface pressure, shielding occupants from external pressure.
• Scuba Gear: Supplies air at the same pressure as the surrounding water, equalizing the pressure in the diver's lungs and airways.
• Habitat Diving: Living in pressurized underwater habitats allows divers to work at depth for extended periods, managing pressure changes carefully during transfer and ascent.
• Saturation Diving: Divers live in pressurized environments and are transported to the work site in a diving bell, minimizing the number of critical pressure changes.

Table: Approximate Water Pressure at Depth

In summary, while deep ocean pressure is incredibly powerful and lethal, its primary threat to the human body isn't crushing the incompressible parts, but rather the severe compression and potential collapse of air-filled spaces.