For every diver, from the newly certified Open Water enthusiast to the seasoned technical explorer, the risk of Decompression Sickness (DCS) is a constant reality. Often called "the bends," DCS is perhaps the most well-known physiological hazard in scuba diving. However, it is also one of the most manageable risks if you understand the science, recognize the symptoms, and follow strict prevention protocols.
In this guide, we will break down exactly what happens to your body under pressure, why technical divers face unique challenges, and how to turn your decompression stops into a safer, more manageable part of your dive plan.
1. The Basics: What is Decompression Sickness?
To understand DCS, we have to look at the physics of diving. When we breathe compressed air at depth, the increased ambient pressure causes our body tissues to absorb more nitrogen (or other inert gases) than they would at the surface. This is based on Henry’s Law.
As long as you remain at pressure, this gas stays dissolved in your tissues. The danger arises during ascent. If you ascend too quickly, the pressure drops rapidly, and that dissolved nitrogen comes out of the solution faster than your body can exhale it. Instead of being safely eliminated through your lungs, it forms bubbles in your blood and tissues—similar to opening a shaken bottle of soda.
Common Scenarios for DCS
While DCS can happen even on dives that stay within "no-decompression limits," certain behaviors significantly increase the risk:
- Rapid Ascents: Exceeding the recommended ascent rate (usually 30 feet/minute).
- Skipping Safety Stops: Missing that crucial 3-minute pause at 15 feet.
- Yo-Yo Diving: Multiple rapid ascents and descents during a single dive.
- Dehydration: Thickened blood impedes inert gas elimination.
- Exertion: Heavy exercise immediately before, during, or after a dive.
Recognizing the Symptoms
DCS symptoms can range from mild irritation to life-threatening emergencies. According to Divers Alert Network (DAN), symptoms often appear within 15 minutes to 12 hours after surfacing.
Common signs include:
- Joint Pain: Deep, aching pain in the elbows, knees, or shoulders (the classic "bends").
- Skin Issues: Itching, rashes, or a marble-like mottling of the skin.
- Neurological Symptoms: Numbness, tingling, paralysis, or dizziness.
- Fatigue: Extreme, unusual exhaustion disproportionate to the dive effort.
- Respiratory Issues: Shortness of breath or a dry cough (known as "the chokes").
2. Decompression Sickness in Technical Diving
Technical diving involves going beyond recreational limits—deeper than 130 feet (40 meters) or staying long enough to incur a mandatory decompression ceiling. While tech divers are highly trained, they face a higher statistical risk of DCS due to the extreme nitrogen (or helium) loading involved.
Why is the Risk Higher?
In technical diving, the "gas loading" is significant. A tech diver might spend 30 minutes at 200 feet, requiring 45 minutes or more of staged decompression stops to surface safely. If a diver loses buoyancy control and shoots to the surface, or if they miscalculate their gas switching, the consequences can be severe. The margin for error is much smaller than in recreational diving.
Treatment Protocols
If a diver suspects they have DCS, immediate action is vital:
- Surface Oxygen: Administer 100% emergency oxygen immediately. This helps flush nitrogen from the body and oxygenate starved tissues.
- Hydration: If the diver is conscious and able to swallow, give non-alcoholic fluids.
- Evacuation: Transport the diver to the nearest medical facility.
- Recompression: The definitive treatment is Hyperbaric Oxygen Therapy (HBOT) in a recompression chamber, which shrinks the bubbles and forces gas back into solution to be exhaled slowly.
Note: For detailed medical guidelines, always refer to authoritative sources like the National Center for Biotechnology Information (NCBI) or DAN.
3. Prevention: The Key to Safe Diving
The best cure for DCS is prevention. Whether you are diving a shallow reef or a deep wreck, safety should never be compromised.
Rigorous Planning
There is an old saying: "Plan the dive, dive the plan." rely on your dive computer, but understand the algorithms behind it. Ensure your surface intervals are long enough to off-gas residual nitrogen, and avoid flying for at least 18-24 hours after diving.
Strict Adherence to Decompression Stops
For recreational divers, the "safety stop" is optional but highly recommended. For technical divers, "deco stops" are mandatory. These stops allow your body to off-gas controlled amounts of nitrogen at specific depths.
However, hanging onto a line at 20 feet for 30 minutes can be mentally challenging. Boredom can lead to complacency, and complacency can lead to drifting depth.
Pro Tip: Managing Long Deco Stops with DIVEVOLK
One of the unique challenges of long decompression stops is simply passing the time while staying alert. This is where the DIVEVOLK SeaTouch 4 Max housing changes the game.
Because our housing utilizes a touchscreen membrane that gives you full access to your smartphone’s functions underwater, you can use your device as a safety and relaxation tool during long hang-times.
- Set Safety Alarms: You can use your phone’s Clock app to set a countdown timer or alarm for your stop duration. This acts as a secondary audible and visual alert to your dive computer.
- Relax with Media: Many technical divers now download movies, e-books, or soothing playlists to their phones. Watching a few minutes of a movie or listening to music can help lower your heart rate and reduce stress during a long deco hang.
Safety Warning: While using your phone can help pass the time, situational awareness is paramount. Never become so absorbed in a movie or book that you lose track of your buoyancy, depth, or gas supply. Your primary focus must always remain on your dive status and your buddy.
Check out our SeaTouch 4 Max Kits to see how you can bring your smartphone’s full functionality on your next deep dive.
Conclusion
Decompression sickness is a serious subject, but with the right knowledge, preparation, and tools, the risk can be minimized. By staying hydrated, diving conservatively, and respecting your decompression stops, you can ensure that every dive ends safely.
Ready to upgrade your dive gear? Explore our full range of underwater housings and discover how full touchscreen access can enhance both your safety and your enjoyment underwater.
