A rapid pressure change. A predictable consequence. A specific treatment.
When a diver breathes any gas containing nitrogen at depth — air, nitrox, or other breathing mixtures — nitrogen dissolves into the body's tissues under pressure. A controlled ascent allows that nitrogen to leave safely. A too-rapid ascent does not. The nitrogen comes out of solution as bubbles — in the bloodstream, in the joints, in the spinal cord, in the brain. The result is decompression sickness: an injury ranging from joint pain and fatigue in milder presentations to neurological damage and paralysis in severe ones.
DCS has a definitive treatment — one that has been the established standard of care in dive medicine for decades. And that treatment is precisely where standard insurance most commonly fails the diver.
Hyperbaric oxygen therapy — the established standard of care
Hyperbaric oxygen therapy (HBOT) works by placing the diver in a pressurized chamber and delivering 100% oxygen at pressures substantially higher than atmospheric. The increased pressure reduces the size of nitrogen bubbles. The high-concentration oxygen accelerates the elimination of nitrogen from the body's tissues and promotes healing in affected areas. It is not an experimental treatment. It is the medically recognized, clinically established response to decompression sickness.
What hyperbaric treatment actually costs
Hyperbaric oxygen therapy is not an inexpensive treatment. A single session at a medical-grade facility — depending on the country, the facility type, and whether it operates within any insurance network — can run from several hundred to well over a thousand dollars or the local currency equivalent. The cost is not the session alone. It is the sessions required, the facility charges, the physician fees, and in many cases the cost of reaching the facility in the first place.
Many presentations of decompression sickness respond to a single Treatment Table 6 session. More serious presentations — particularly those involving neurological symptoms — may require additional sessions. The total cost of treatment before evacuation, accommodation, and associated medical expenses are added can reach into the thousands. In remote locations, where the chamber facility itself may require significant travel to reach, the financial exposure begins before the diver enters the chamber.
The gap operates differently depending on which policy a diver carries — and in each case it is real
The access gap. Many domestic health insurance systems — whether national, employer-provided, or privately purchased — do recognise hyperbaric oxygen therapy as a legitimate medical treatment for decompression sickness. The problem is not recognition. It is access. Coverage typically applies only at approved, in-network, or locally registered facilities. The nearest hyperbaric chamber to a dive emergency — particularly in a remote or international location — is rarely within that network. The coverage that exists at home does not follow the diver to the water.
The exclusion gap. Standard travel insurance presents a different and more fundamental problem. Travel policies routinely exclude scuba diving incidents entirely, restrict coverage to recreational depths only, or classify diving as a hazardous activity from which medical claims are excluded. DAN's own published guidance states directly that chamber treatments are not typically covered by standard travel insurance. This is not a network problem. It is an exclusion written into the policy before the diver purchases it.
The portability gap. For divers travelling internationally, both problems converge with a third: domestic health coverage, wherever it originates, may simply not be accepted at a foreign treating facility. A policy that provides full coverage at home may have no practical value in the country where the diver is treated. The diver arrives at the chamber facility effectively uninsured — regardless of what their policy says — because the facility has no means of verifying or processing that coverage in real time.
There is an additional dimension that no insurance policy can address directly: in some settings, financial incentives may influence the amount or type of care recommended. A diver without expert medical advocacy has no independent check on what is being prescribed. A diver with access to DAN's emergency hotline has a dive medicine physician who knows what the condition actually requires — and who can communicate directly with the treating facility to ensure that clinical decisions reflect the diver's medical needs. This is not an insurance provision. It is medical protection that operates independently of the policy — and is available to anyone who calls, member or not.
The language that matters and the language that does not
A policy that covers "emergency medical treatment" does not necessarily cover hyperbaric oxygen therapy. A policy that covers "diving accidents" does not necessarily cover the treatment that diving accidents require. The specific coverage that a diver needs to verify is explicit, named, and unambiguous — and it must be verifiable in the policy document itself, not assumed from a summary or a sales conversation.
Dive-specific insurance — through DAN's global network of regional entities, DiveAssure, and appropriately configured dive travel policies — is built explicitly around these requirements. Hyperbaric oxygen therapy for decompression sickness is a named, covered treatment, not an assumed one. The policy is designed around what dive medicine actually involves, not what general insurance assumes it might.
You know what this gap is and where it lives. Which coverage closes it depends on where you are based and how you dive. Plan & Profile is the next step.
The Hyperbaric Gap is the first gap. It is not the only one.
A diver who understands the hyperbaric gap understands the foundational logic of all five coverage gaps in dive accident insurance. The pattern is consistent: standard policies are built for standard medical situations. Dive accidents introduce costs, treatments, and logistical realities that fall cleanly outside what those policies were designed to address.
The remaining four gaps — evacuation from remote sites, rescue services, repatriation, and specialist consultation — each follow the same logic and each deserve the same scrutiny. The diver who works through all five before entering the water is in a fundamentally different position from the diver who discovers any one of them in the field.