19/07/2026
𝐂𝐄𝐒𝐀: 𝐒𝐨𝐥𝐮𝐭𝐢𝐨𝐧 𝐅𝐨𝐫 𝐘𝐞𝐬𝐭𝐞𝐫𝐝𝐚𝐲'𝐬 𝐏𝐫𝐨𝐛𝐥𝐞𝐦
𝐖𝐡𝐚𝐭 𝐢𝐬 𝐢𝐭?
CESA (Controlled Emergency Swimming Ascent) is a last-resort emergency procedure still taught by many recreational diving agencies for the unlikely situation in which a diver has completely lost access to breathing gas and no alternate gas source is available. Under the right circumstances, when performed correctly and without additional complications, CESA can be successful. The real question, however, is whether modern diver training should continue placing significant emphasis on a procedure that becomes relevant only after multiple preventive safety barriers have failed or are no longer available. From a UTD/DIR perspective, the priority should not be teaching divers how to escape that situation. It should be ensuring they are unlikely to ever end up in it—and, if they do, that they can resolve it calmly, under control and (preferably) as a team.
𝐌𝐨𝐝𝐞𝐫𝐧 𝐝𝐢𝐯𝐢𝐧𝐠 𝐜𝐡𝐚𝐧𝐠𝐞𝐝 𝐭𝐡𝐞 𝐪𝐮𝐞𝐬𝐭𝐢𝐨𝐧
Decades ago, when buddy breathing was common practice and standardized gas donation was not yet common, CESA was a logical solution. Today, modern diving no longer starts with the emergency. It starts with preventing the emergency. Instead of asking: "How do we survive after running out of gas?" it asks: "How do we prevent a diver from ever having to make an emergency ascent?" That shift in philosophy changes everything.
𝐀 𝐬𝐲𝐬𝐭𝐞𝐦 𝐢𝐧𝐬𝐭𝐞𝐚𝐝 𝐨𝐟 𝐚 𝐬𝐢𝐧𝐠𝐥𝐞 𝐬𝐤𝐢𝐥𝐥
This is where the UTD/DIR philosophy fundamentally differs.
Instead of building safety around a single emergency procedure, it builds safety around multiple independent layers designed to prevent emergencies long before they occur. Continuous gas awareness. Rock Bottom gas planning. Buddy proximity. Standardized equipment and procedures. Standardized long hose gas donation. Precise buoyancy. Stable trim. Efficient propulsion. Predictable ascents. Each layer exists to prevent the next layer from ever becoming necessary. Rock Bottom is a good example. It is not simply reserve gas. It is the minimum amount of gas deliberately "protected" so that two divers can resolve an out-of-gas emergency, establish gas sharing and complete a controlled ascent together. The objective is not simply to survive an out-of-gas emergency. The objective is to avoid ever needing an emergency ascent. In UTD/DIR, CESA is not replaced by another emergency procedure. It is replaced by a system designed to make it unnecessary.
𝐖𝐡𝐲 𝐝𝐨𝐞𝐬 𝐭𝐡𝐢𝐬 𝐦𝐚𝐭𝐭𝐞𝐫?
As I explained in my previous article, every ascent is decompression. The ascent is not merely the end of the dive. It is one of the most important parts of it. Within the UTD/DIR framework, every ascent is planned before the dive even begins. It is predictable. It is controlled. It is repeatable. Buoyancy, trim and team awareness are maintained throughout the ascent—not abandoned because an emergency has occurred. A genuine out-of-gas emergency without maintaining that level of control makes the whole situation significantly more difficult. Stress increases breathing rate. Trim deteriorates. Buoyancy becomes harder to control. Ascent rates often increase unintentionally. Loss of buoyancy and ascent control increases the risk of ascent-related injuries, including pulmonary barotrauma, arterial gas embolism (AGE) and pneumothorax, while also increasing decompression stress compared with a well-controlled, predictable ascent. Even reaching the surface does not necessarily end the emergency. Boats. Propellers. Jet skis. Current. Waves. The emergency has not necessarily ended—it has simply changed, or it may even have escalated.
𝐓𝐡𝐞 𝐫𝐞𝐚𝐥 𝐝𝐢𝐬𝐜𝐮𝐬𝐬𝐢𝐨𝐧
CESA still has a place—as an absolute last resort within training systems that rely on it because they lack or don't put enough emphasis on multiple preventive layers of safety. The question is not whether divers should understand what CESA is. The question is how much training time should be devoted to a procedure intended for a scenario that modern diving systems are specifically designed to prevent. From a UTD/DIR perspective, CESA should no longer be considered a cornerstone of modern diver education because it addresses the failure, not the system that allowed the failure to occur. Training time is limited. Every minute spent practicing a procedure designed for multiple simultaneous failures is a minute not spent mastering the skills divers rely on during every single dive: precise buoyancy, stable trim, efficient propulsion, continuous gas awareness, Rock Bottom gas planning, standardized equipment, team procedures, predictable ascents... Those skills don't simply improve diving. They are the layers of safety that make CESA increasingly unnecessary. Modern diver training should focus less on teaching divers how to escape catastrophic failures...and more on building a system in which those catastrophic failures are far less likely to occur—and, if they do occur, can be managed calmly, under control and as a team. CESA is not the problem. Needing CESA is. CESA solved yesterday's problem. Modern diving should build systems—not emergency swimming ascents.
