What Is Freediving? A Clear Explanation of the Sport
What freediving actually involves - how it works, the disciplines within the sport, the mammalian dive reflex, world records, how it compares to scuba, and whether it might be right for you.
Safety First
Freediving always requires a trained buddy. Never practice breath-hold diving alone - shallow water blackout can occur without warning and is survivable only if someone is present to respond.
Freediving is diving underwater on a single breath. No tanks, no regulators, no hoses. Just your lungs, the water, and however long you can stay down.
The simplicity is part of the appeal. You enter the water with a mask, fins, and possibly a wetsuit. You breathe up at the surface, exhale partially, and descend. At the bottom - whether that’s 5m in a warm lagoon or 30m on a breath-hold training session - you float or move or observe, then ascend. When you breach the surface, you breathe again.
That’s the whole thing.
How It Physically Works
The human body has a set of reflexes collectively called the mammalian dive reflex - involuntary physiological responses to breath holding and immersion in water. These are not uniquely human; they exist in all air-breathing mammals that swim.
When you submerge your face in water, your heart rate drops. This is called bradycardia. Blood is redistributed away from your extremities and toward your vital organs - heart, lungs, brain. Your spleen contracts and releases oxygen-rich red blood cells into circulation. As you descend to depth, your lungs compress under pressure and blood shifts into the thoracic cavity to prevent the chest from collapsing.
These responses mean the human body is more adapted to diving than most people realize. They also mean the body adapts measurably with training - experienced freedivers show stronger dive reflexes than untrained individuals, and their heart rate drops faster and further during dives.
The Disciplines
Freediving has a range of competitive and training disciplines, each testing different aspects of breath-hold performance:
Static Apnea (STA) - floating face-down in a pool and holding your breath as long as possible. No movement, no depth. Tests pure breath-hold duration. Competition world record exceeds 24 minutes.
Dynamic Apnea (DYN / DNF) - swimming horizontally underwater on one breath, either with fins (DYN) or without (DNF). Distance is the metric. Tests how far you can travel in a single breath.
Constant Weight (CWT / CNF) - vertical depth diving with fins (CWT) or without fins (CNF). The most recognized freediving discipline. You descend under your own power and ascend the same way, without pulling on the line. Competition depth exceeds 100m.
Free Immersion (FIM) - pulling down and up a rope without fins. A recovery technique for divers learning equalization.
No Limits (NLT) - using any means to descend and ascend, typically a weighted sled and inflatable bag. No longer in active competition due to risk, but produced the deepest recorded freedives - Herbert Nitsch at 214m in 2007 (unofficial) and 253m in 2012 before a decompression accident on ascent.
Most recreational freedivers work in constant weight - descending and ascending vertically, which is what “going freediving” typically means.
Freediving vs Scuba Diving
Scuba involves carrying compressed air in a tank and breathing continuously throughout a dive. The advantage is unlimited bottom time - you stay down as long as your air supply lasts. The limitation is the equipment: a BC, regulator, tanks, and weight system that collectively weigh 15-25kg.
Freediving carries none of that. The experience is quieter, less encumbered, and more intimate with the water. Marine life - fish, dolphins, whales - reacts differently to a silent, tank-free diver than to the constant bubbling of a scuba set.
The limitation is time: a breath hold ends when your body requires oxygen. Recreational freedivers spend 1-3 minutes per dive at depth. What you can observe and experience in that window is limited by depth and the environment, but many divers find it more focused and satisfying than extended scuba dives for that reason.
The two sports are not mutually exclusive. Many divers do both, using freediving for shallow reef exploration and spearfishing, and scuba for deeper wrecks or extended observation.
Spearfishing
Many freedivers begin as spearfishers, or come to freediving through the spearfishing community. The skills transfer directly - breath hold, descent technique, equalization, and diving in open water are the same foundations.
Spearfishing has its own specific considerations around local regulations, species restrictions, and marine protected areas. Those are beyond this guide’s scope, but the skill foundation is identical.
Is Freediving Right for You?
The sport suits people who are comfortable in open water (not just a swimming pool), physically fit enough for sustained swimming, and patient enough to develop the mental side of breath holding. It’s not about being a gifted swimmer - it’s about relaxation, controlled technique, and progressive depth work over months.
The fastest path to progression: a beginner course, regular pool training with a buddy, and time in the water. Details on how to start: How to Start Freediving.
Frequently Asked Questions
Is freediving the same as breath-hold diving?
How long can freedivers hold their breath?
How deep can freedivers go?
Is freediving dangerous?
Do I need certification to go freediving?
Marcus Webb
Freediving Instructor & Gear Reviewer
Marcus Webb has been freediving for over nine years, training in Dahab, the Philippines, and along the California coast. He holds a PADI Advanced Freediver certification and AIDA 2* and has completed over 1,200 logged dives across static apnea, dynamic, and depth disciplines. He reviews every piece of gear he recommends from personal use — he does not accept payment for positive coverage.