Written by Decompression sickness (DCS), also known as “the bends,” is a serious condition that occurs when a diver ascends too quickly after spending time at depth. As a diver descends, nitrogen gas from the air becomes dissolved in the body due to higher pressures. If a diver ascends too quickly, the nitrogen bubbles out of solution and forms gas emboli, which can cause damage to tissues and organs. Preventing DCS is crucial for maintaining your health and safety underwater.
In this post, we’ll cover practical tips and strategies for decompression sickness prevention, ensuring a safe and enjoyable diving experience.
What Is Decompression Sickness?
Decompression sickness happens when nitrogen, which is dissolved in the body tissues at high pressure, forms bubbles as the diver ascends and the pressure decreases. These bubbles can block blood flow, causing damage to tissues and organs, which may result in severe pain or even life-threatening conditions.
Symptoms of Decompression Sickness:
- Joint and muscle pain (resembling “the bends”)
- Dizziness, nausea, and vomiting
- Shortness of breath and chest pain
- Paralysis or difficulty moving limbs
- Fatigue and confusion
Decompression Sickness Prevention Tips
1. Adhere to Safe Ascension Rates
One of the most important rules to prevent DCS is to ascend slowly and at a controlled rate. A general guideline is to ascend no faster than 9-10 meters per minute (30 feet per minute). Slower ascents allow the body to expel nitrogen gradually.
Why It’s Important:
- During slower ascents, nitrogen has time to safely leave your tissues and be exhaled through your lungs.
- Rapid ascents may cause nitrogen bubbles to form too quickly, increasing the risk of DCS.
Pro Tip: If you start feeling any discomfort during your ascent, slow down or pause to allow your body to adjust.
2. Perform Safety Stops
A safety stop is a precautionary measure to give your body time to off-gas any residual nitrogen before reaching the surface. It’s typically done at a depth of around 3-5 meters (10-15 feet) for 3 to 5 minutes after a dive, especially if you’ve been at depths greater than 10 meters or have made multiple dives in a day.
Why It’s Important:
- It allows nitrogen to be expelled safely from your body without the risk of forming harmful bubbles.
- It’s an added safety measure, even if you haven’t reached decompression limits.
Pro Tip: Always perform a safety stop, even if you haven’t exceeded no-decompression limits, for added safety.
3. Plan Your Dives Properly
Planning each dive with a dive table or a dive computer is crucial to ensuring you stay within safe depth and time limits. Dive tables and computers provide no-decompression limits and suggest safe ascent profiles based on depth and time underwater.
Why It’s Important:
- Proper dive planning reduces the risk of staying at depths too long and accumulating too much nitrogen.
- It helps avoid exceeding your no-decompression limits, reducing the likelihood of DCS.
Pro Tip: Plan multiple dives carefully. Avoid deep or prolonged dives when you plan to make multiple dives in a single day, as this can lead to excessive nitrogen absorption.
4. Stay Hydrated
Dehydration can increase the likelihood of DCS because it reduces the volume of blood and the ability to transport nitrogen to the lungs for exhalation. It’s essential to drink plenty of water before, during, and after diving.
Why It’s Important:
- Dehydrated divers are at greater risk of nitrogen retention in tissues, leading to a higher chance of developing DCS.
- Hydration helps with the body’s ability to eliminate excess nitrogen safely.
Pro Tip: Drink water throughout the day, especially on dive days, and avoid alcohol or caffeine, which can dehydrate you.
5. Avoid Diving While Fatigued or Sick
Your body is more vulnerable to DCS when you’re physically weak or unwell. Diving while fatigued, hungover, or sick can impair your body’s ability to handle the nitrogen load, increasing the risk of developing DCS.
Why It’s Important:
- Illness and fatigue can impair your circulation and respiratory efficiency, making it harder for your body to off-gas nitrogen.
- Your mental focus may be diminished, leading to risky diving behaviors.
Pro Tip: Always ensure you’re in optimal health and well-rested before a dive, and avoid diving if you feel unwell.
6. Use Proper Dive Profiles for Deep and Extended Dives
For deeper dives or dives beyond recreational limits, you may need to use decompression tables or a dive computer that accounts for the possibility of decompression stops. These tools will help you plan your ascent profile more accurately and avoid exceeding your nitrogen saturation limits.
Why It’s Important:
- Deeper dives increase the amount of nitrogen dissolved in the body, and an appropriate ascent profile helps manage this risk.
- Accurate dive planning and stops help to prevent nitrogen build-up in tissues that could lead to DCS.
Pro Tip: For dives requiring decompression stops, it’s crucial to follow the dive plan and stop at the prescribed depths and times.
7. Avoid Multiple Dives Without Sufficient Surface Intervals
When performing multiple dives in one day, ensure you have enough surface time between dives to allow your body to expel the nitrogen absorbed during each dive. The recommended surface interval is typically at least 1 hour between dives, but longer intervals are recommended for deeper or longer dives.
Why It’s Important:
- Multiple dives within a short period can increase nitrogen absorption, and insufficient surface intervals can lead to nitrogen retention.
- Giving your body enough time to off-gas between dives reduces the likelihood of DCS.
Pro Tip: Take longer surface intervals for deep or long dives to give your body ample time to expel nitrogen.
Decompression Sickness First Aid
In case of suspected decompression sickness, immediate action is critical. The symptoms can develop within minutes to hours after surfacing. If any symptoms of DCS occur, seek medical help immediately. The treatment for DCS typically involves hyperbaric oxygen therapy (HBOT), which helps reduce the size of nitrogen bubbles and accelerates nitrogen off-gassing.
Pro Tips and Takeaways for DCS Prevention:
- Ascend slowly: No faster than 9-10 meters per minute.
- Always perform a safety stop: 3-5 meters for 3-5 minutes.
- Hydrate well: Avoid dehydration before and after your dives.
- Plan your dives: Use dive tables or computers to track dive time and depth.
- Avoid fatigue or illness: Only dive when you’re physically prepared.
- Use proper dive profiles: For deep or extended dives, ensure you’re aware of decompression limits.
Q&A: Common Questions about Decompression Sickness Prevention
Q1: Is a safety stop really necessary for every dive?
A1: Yes, even for shallow dives, a safety stop is a good practice to allow your body time to expel residual nitrogen. It’s an added layer of safety.
Q2: How long should I wait before diving again after a long dive?
A2: It’s best to wait at least 24 hours before making another deep dive to allow your body to fully off-gas any nitrogen from previous dives.
Q3: Can I prevent DCS by just diving shallow?
A3: While diving shallow reduces the risk of DCS, you still need to follow proper dive planning, ascension rates, and safety stops to minimize nitrogen absorption.
Q4: What if I feel symptoms of DCS after a dive?
A4: If you experience symptoms such as joint pain, dizziness, or shortness of breath, seek emergency medical help immediately. Prompt treatment, like hyperbaric oxygen therapy, is essential.
Conclusion
Preventing decompression sickness is all about managing nitrogen absorption and ensuring a safe ascent from depth. By following safe diving practices such as ascending slowly, performing safety stops, and staying hydrated, you can reduce the risk of DCS significantly. Always plan your dives carefully, and if you’re diving deep or performing multiple dives, give your body the time it needs to off-gas. Dive safely, plan carefully, and stay within your limits to enjoy a long and healthy diving career.
*Disclaimer: The content in this post is for informational purposes only. The views expressed are those of the author and may not reflect those of any affiliated organizations. No guarantees are made regarding the accuracy or reliability of the information. Use at your own risk.