Today, shows in oceanariums are seeing a real surge in popularity. Inside massive aquariums, people organize photo shoots, teach freediving, and put on large theatrical productions, ranging from underwater ballet to elaborate costumed performances. Yet, behind this flawless appearance is a profession that truly deserves to be called one of the most overlooked and physically demanding in the world.
Aquarium performers
What is really behind the beautiful image, and why does performing in an underwater show pose health risks?
Aquarium performers face unique challenges beneath the surface.Here, the main stars are the fish, not the people.
The first and most deceptive enemy for the performer is temperature. While professional freedivers and scuba divers always go underwater in protective wetsuits that help keep their body heat, a “mermaid” does not have that option. She must perform in an open top and a tail. In aquariums, it is the needs of the marine animals that set the conditions, not human comfort. Fish, rays, and sharks are sensitive to their environment, so the chemical makeup and temperature of the water are closely controlled for their benefit.
In most commercial oceanariums, the water temperature is kept at 21-22 °C. For someone doing physical work, a comfortable water temperature is at least 27-28 °C. Lack of protection. Professional divers and freedivers wear neoprene wetsuits between 3 and 7 mm thick, which hold a thin layer of water next to the skin and warm it. Performers, on the other hand, appear in open costumes tops and fabric or silicone tails worn directly on bare skin.
During a typical shift, a performer makes dozens of dives. In these conditions, the body loses heat 25 times faster than it does in air. Carbon dioxide buildup and constant muscle strain cause faster calorie loss and a drop in body temperature. Calf and foot cramps in cold water are a regular part of the job.
Even when rules allow a performer to wear a thin wetsuit under the stage costume (such as at deep-water venues in the UAE), another issue comes up: buoyancy. Neoprene contains air bubbles and pushes a person up toward the surface. To balance this and be able to sink to the bottom, the performer has to wear weight belts with lead plates weighing from 4 to 8 kilograms. This puts much more strain on the spine and joints.
The physiology of depth: barotrauma, pressure, and working with limited vision
The deeper the aquarium, the harsher the environment becomes. At depth, the performer’s body is under the pressure of a huge mass of water. The main challenge is to equalize pressure regularly and without the audience noticing. Regular divers use masks that cover both eyes and nose, making it easier to equalize pressure. Mermaids, though, perform with their faces exposed, using only a nose clip and goggles, and sometimes employers want them to perform without goggles as well.
Working without a mask means the eyes are in direct contact with seawater or chlorinated water. The salt content in oceanarium water is harsh on the eye’s mucous membrane. Without a mask, the performer’s vision becomes blurry; the shapes of the scenery, fish, and even the glass wall become hard to make out. Wearing contact lenses in salt water is very risky: if a lens gets washed out or salt gets underneath it, it causes a sudden spasm and pain. Aquarium performers
Muscle isolation and the “caterpillar effect”
The biggest illusion of an underwater show is the look of effortless movement. To the audience, moving slowly and gracefully in water seems easy. In reality, the slower and smoother the movement, the more strength and control it actually takes.
Beginners trying to swim in a tail often make the same mistake: they bend their knees, making quick, jerky kicks with their thighs. This looks awkward (the so-called “caterpillar walk”) and quickly uses up oxygen.
Professional technique means starting a smooth, wave-like motion through the whole body. The wave begins at the back of the head and upper spine, moves through the lower back, hips, and thighs, and finally reaches the monofin.
Systemic hypoxic stress and safety procedures
Working while holding your breath demands strong anaerobic conditioning. A typical dive lasts from 45 to 90 seconds, after which the performer surfaces to breathe, takes a short break (30-45 seconds), and dives again. This pattern is called interval hypoxic training. During repeated dives without full recovery, lactic acid (lactate) builds up in the blood. Muscles get tired, and coordination gets worse. The main urge to breathe comes not from a lack of oxygen but from the buildup of carbon dioxide (CO2) in the blood.
The performer must be able to resist the urge to breathe (diaphragm contractions) while keeping a neutral facial expression underwater. Losing consciousness from hypoxia (blackout) is a real danger in freediving. Because of this, professional aquarium rules always require a safety diver with a scuba tank and an octopus regulator to be present at depth or on the surface.
The evolution of the industry: from aquarium entertainment to underwater ballet
Shows in oceanariums have long moved past just swimming in front of the glass. Now, they are a full part of the entertainment industry, where performers are expected to have the skills of a dramatic actor, synchronized swimmer, and gymnast. Performing as a pair or group underwater is made harder by the lack of sound cues (unless underwater speakers are used). Performers rely completely on visual contact and their own sense of rhythm. Using underwater fabrics, hoops, and heavy costume pieces requires careful calculation of the weight and buoyancy of each item. Any mistake in balancing can pull the performer down or keep them from surfacing in time.
Underwater performances in oceanariums are a complex commercial industry. Behind the visual lightness and colorful spectacle are hours of training in cold water, barometric stress on the performers’ bodies, a constant fight with hypoxia, and hard physical work. This job demands that performers have the preparation of professional athletes and work every day at the edge of human ability.
Photo courtesy of the author.
Back to Home
This post was last modified on September 5, 2026 2:48 am