Scuba diving during menstruation is generally safe. Concerns about diving during a menstrual cycle are widespread, but they are based more on myths and logistical worries than on physiological barriers. Understanding the body’s response underwater and having appropriate preparation ensures a comfortable and uninterrupted diving experience. Modern hygiene products and a conservative approach to dive planning address nearly all potential issues.
Feasibility and Physiological Impacts of Diving
Menstruation itself presents no physical obstacle to enjoying the underwater world. Hormonal changes may lead to temporary symptoms like fluid retention, causing bloating or affecting the fit of a wetsuit. This slight swelling can make donning tight exposure suits more uncomfortable than usual.
The primary physiological concern raised is a theoretical link between menstruation and an increased risk of Decompression Sickness (DCS). Hormonal shifts can cause fluid retention and tissue swelling, which could, in theory, hinder the elimination of nitrogen from the body. While some studies suggest a minor correlation, the Divers Alert Network (DAN) consensus is that the risk is negligible for recreational divers following standard safety protocols.
Divers must be mindful of their overall physical state, as fatigue, dehydration, and general discomfort increase DCS risk. Since menstruation can sometimes be accompanied by these symptoms, prioritizing increased hydration and sufficient rest is a sensible precaution. If a diver experiences significant abdominal cramping, over-the-counter pain relievers can manage discomfort and improve concentration underwater.
Some research suggests that women taking oral contraceptives may benefit from diving more conservatively, meaning shorter and shallower dives with longer safety stops, especially during the menstrual phase. A heightened sense of feeling cold is also reported by some menstruating divers. This may warrant wearing a slightly thicker wetsuit or hood for thermal comfort.
Dispelling the Shark Myth
The most persistent fear surrounding diving during menstruation is that the blood attracts sharks and increases the risk of an attack. This concern is widely debunked by shark researchers and diving safety organizations. The volume of blood released is extremely small, averaging only about 80 milliliters over several days, and is primarily composed of tissue and mucus, not fresh blood.
For a diver using an internal hygiene product, the chance of any detectable amount of blood entering the water is minimal. Sharks are highly attuned to the specific amino acids found in the fluids of their typical prey, such as fish and marine mammals, not humans.
Expert divers, including marine biologists, have repeatedly dived with sharks while menstruating without incident. Divers regularly enter the water with minor cuts or scrapes that release small amounts of fresh blood without increasing shark encounters. Consequently, there is no data to support the idea that menstruating divers are at a greater risk of a shark bite.
Practical Management and Hygiene Underwater
Managing hygiene effectively is the most actionable aspect of diving while menstruating. Traditional adhesive pads are completely unsuitable for diving because they cannot function when saturated with water. Internal products are required, and the menstrual cup is considered the superior option for underwater activities.
Menstrual cups are made of medical-grade silicone and collect flow rather than absorbing it, meaning they do not swell or lose effectiveness in water. They create a secure seal that prevents leaks and can be worn for up to twelve hours, which is ideal for long dive days with multiple immersions. Tampons are a viable alternative, though they may absorb water and can become slightly uncomfortable, often requiring a change between dives.
Dive Boat Logistics
The close-fitting nature of a wetsuit or drysuit provides an additional layer of security, as the compression generally prevents any external leakage while underwater. On a dive boat, discretion and planning are important, especially when using a shared head or bathroom facility. Carrying a small, opaque bag with extra supplies, wet wipes, and a designated disposal method for used products ensures smooth transitions between dives. For those using a menstrual cup, having a bottle of fresh water for rinsing the cup in private on the boat simplifies the hygiene process.