Underwater caves – beautiful and dangerous

Underwater caves are significant for geological and biological research, as well as for scuba diving exploration. These natural rock formations can be found in both marine waters and freshwater lakes and rivers. They come in the form of tunnels, corridors, chambers, and systems stretching for dozens of kilometers. For scientists, they are a treasure trove of knowledge about Earth’s past; for divers, an exhilarating adventure; and for most of us, a mystery we are unlikely to explore.

Mechanisms of underwater cave formation

The formation of underwater caves is a lengthy process influenced by various geological and hydrological factors. Three primary mechanisms are responsible for creating these structures:

• Erosion of rocks by water
  Erosion primarily affects limestone and gypsum, which dissolve under the influence of water. The formation of corridors and chambers can take millions of years, with many existing underwater caves having once been dry grottos.
• Volcanic activity
  Volcanic eruptions can create lava tunnels, which, after being submerged, transform into underwater caves. These formations are most commonly found in regions with high volcanic activity.
• Tectonic phenomena
  Underwater caves can also form due to tectonic plate movements. This process creates cracks and sinkholes that eventually fill with water, resulting in expansive and often very deep cave systems.

The most famous underwater caves

The world is home to many underwater cave systems with diverse lengths and characteristics. Here are some of the most renowned examples:

• Sistema Dos Ojos
  Located on the Yucatán Peninsula, this system is one of the longest in the world, with corridors spanning over 80 km. The name Dos Ojos comes from its two entrances, which resemble eyes. The water here is exceptionally clear. During exploration, numerous archaeological treasures, including prehistoric human and animal remains, have been discovered.
• Blue Hole
  Situated in Dahab on Egypt’s Sinai Peninsula, the Blue Hole exceeds 100 meters in depth. It is famous for The Arch, a tunnel connecting the cave to the open sea at a depth of 56 meters. This site is immensely popular among divers but is also considered one of the most dangerous, earning the nickname Diver’s Cemetery due to numerous fatal accidents.
• Orda Cave
  The world’s longest known gypsum cave is located in Russia’s Perm region. It stretches over 5 km, most of which is underwater. The cave is distinguished by its extraordinarily clear water, offering visibility for dozens of meters.

Challenges and dangers of exploration

Underwater caves are some of the most challenging and dangerous places for divers to explore. These unique environments require not only experience and specialized skills but also meticulous planning and proper equipment. Even the smallest mistake can have serious, sometimes fatal consequences, making it essential to fully understand the risks involved.

One of the greatest dangers in underwater caves is the lack of natural light. These are spaces where no sunlight penetrates, leaving flashlights as the sole source of illumination. If equipment fails, divers can lose their orientation and become lost, often leading to tragic outcomes. Another critical issue is the limited air supply. Every minute underwater requires precise planning, leaving little room for error.

The complex structure of underwater caves—with numerous corridors and tunnels that look similar—makes navigation extremely difficult. Even experienced divers can become disoriented in these labyrinths, which is why navigation techniques and marking routes are absolutely essential. Additional challenges include the risk of decompression sickness. During deep dives, gradual ascent is necessary to avoid severe health issues caused by sudden pressure changes.

Underwater caves are also extremely sensitive ecosystems, where even the slightest human interference can impact the environment. Divers entering these caves must be fully aware of their responsibility to nature.