Tips for Avoiding Decompression Sickness (DCS) While Diving
Decompression Sickness (DCS), also known as "the bends," is a potentially serious condition that can affect divers when dissolved gases, primarily nitrogen, come out of solution and form bubbles in the body's tissues and bloodstream. While DCS can be frightening, understanding the risks and following best practices can significantly reduce your chances of experiencing it. This article provides practical tips to help you dive safely and avoid DCS.
1. Proper Dive Planning and Execution
Careful dive planning is the foundation of safe diving. It involves considering various factors to ensure a dive profile that minimises nitrogen absorption and allows for safe decompression.
Plan your dive and dive your plan: Before every dive, meticulously plan your route, depth, bottom time, and ascent profile. Stick to this plan throughout the dive, and don't exceed your planned limits. This includes maximum depth and no-decompression limits.
Use dive tables or dive computers: Dive tables and dive computers are tools designed to help you calculate safe dive profiles. If using dive tables, understand their limitations and err on the side of caution. Dive computers continuously monitor your depth and time, providing real-time information about your nitrogen loading and decompression requirements. Ensure you are proficient in using whichever tool you choose. Consider our services for dive training.
Consider the dive site conditions: Assess the current, visibility, temperature, and potential hazards of the dive site. Strong currents can increase exertion and nitrogen absorption. Poor visibility can lead to disorientation and exceeding planned depths. Cold water can increase the risk of hypothermia, which can also affect decompression.
Communicate with your buddy: Discuss the dive plan with your buddy before entering the water. Ensure you both understand the plan and are comfortable with it. Maintain constant communication throughout the dive and be prepared to assist each other if needed.
Avoid repetitive dives: Multiple dives in a short period increase your nitrogen loading. If you are doing repetitive dives, plan them conservatively, allowing sufficient surface intervals to off-gas nitrogen. Dive computers will typically account for residual nitrogen from previous dives.
Gradually increase depth on subsequent dives: If you are doing multiple dives over several days, avoid starting with the deepest dive. Allow your body to acclimatise gradually to the pressure changes.
Common Mistakes to Avoid in Dive Planning
Rushing the planning process: Taking shortcuts or failing to thoroughly consider all factors can lead to errors in your dive plan.
Ignoring dive computer warnings: Treat warnings from your dive computer seriously and take appropriate action. Ignoring these warnings can significantly increase your risk of DCS.
Exceeding no-decompression limits: Staying longer or going deeper than your no-decompression limits requires mandatory decompression stops, which increase the risk of DCS if not executed correctly.
2. Ascent Rate Management
Ascent rate is a critical factor in preventing DCS. A slow, controlled ascent allows nitrogen to be gradually released from your tissues, minimizing bubble formation.
Adhere to recommended ascent rates: Most dive computers and training agencies recommend an ascent rate of around 9 metres (30 feet) per minute. Monitor your ascent rate closely and adjust your buoyancy as needed to maintain a slow, controlled ascent.
Make safety stops: A safety stop at 5 metres (15 feet) for 3-5 minutes allows for additional off-gassing and provides an opportunity to monitor for any signs of DCS. This is a standard practice for most dives, even if not required by your dive computer.
Avoid rapid ascents: Rapid ascents are a major risk factor for DCS. They can overwhelm your body's ability to eliminate nitrogen, leading to bubble formation. If you experience an uncontrolled ascent, immediately descend to a safe depth and continue a slow, controlled ascent with a safety stop.
Use a visual reference: When ascending, use a visual reference, such as a dive line or the reef, to help maintain a consistent ascent rate. This is especially important in open water where there are no fixed points of reference.
Scenarios Where Ascent Rate is Critical
Deep dives: On deeper dives, the pressure changes are more significant, making ascent rate even more critical.
Cold water dives: Cold water can slow down nitrogen elimination, requiring even slower ascent rates.
Dives with strong currents: Strong currents can make it difficult to control your ascent rate. Choose dive sites with manageable currents or dive during slack tide.
3. Hydration and Nutrition
Proper hydration and nutrition play a vital role in maintaining overall health and optimizing your body's ability to handle the stresses of diving.
Stay well-hydrated: Dehydration can thicken your blood, making it harder for nitrogen to be transported and eliminated. Drink plenty of water before, during, and after diving. Avoid excessive caffeine and alcohol, as they can have a diuretic effect and lead to dehydration.
Eat a balanced diet: A healthy diet provides the necessary nutrients to support your body's functions. Avoid heavy, fatty meals before diving, as they can slow down digestion and increase the risk of nausea. Choose light, easily digestible foods.
Avoid alcohol before diving: Alcohol can impair judgment, coordination, and reaction time, increasing the risk of accidents. It can also dehydrate you and interfere with nitrogen elimination.
Practical Tips for Hydration and Nutrition
Carry a water bottle: Keep a water bottle with you and sip on it throughout the day.
Eat fruits and vegetables: These are rich in water and nutrients.
Avoid sugary drinks: These can dehydrate you and provide empty calories.
4. Avoiding Strenuous Activity After Diving
Strenuous activity after diving can increase blood flow and potentially dislodge microscopic bubbles that may have formed during the dive. This can increase the risk of DCS.
Avoid heavy lifting: Refrain from lifting heavy objects immediately after diving.
Limit strenuous exercise: Avoid intense workouts or other strenuous activities for several hours after diving.
Stay relaxed: Allow your body to rest and recover after diving.
Why Rest is Important After Diving
Rest allows your body to continue eliminating nitrogen without the added stress of physical exertion. This helps to minimize the risk of bubble formation and DCS. If you're unsure about any activity, learn more about Divemaster and consult with a diving professional.
5. Understanding Risk Factors
Certain factors can increase your susceptibility to DCS. Understanding these risk factors allows you to take extra precautions and minimize your risk.
Age: Older divers may be more susceptible to DCS due to age-related changes in physiology.
Obesity: Excess body fat can increase nitrogen absorption and slow down elimination.
Dehydration: As mentioned earlier, dehydration can thicken your blood and impair nitrogen elimination.
Fatigue: Fatigue can weaken your body's ability to handle the stresses of diving.
Cold water: Cold water can constrict blood vessels and slow down nitrogen elimination.
Patent Foramen Ovale (PFO): A PFO is a small opening between the heart's atria that can allow bubbles to bypass the lungs and enter the arterial circulation, increasing the risk of DCS. If you have a PFO, consult with a diving physician about the risks and precautions.
Mitigating Risk Factors
While you can't change your age or genetic predisposition, you can manage other risk factors by staying hydrated, maintaining a healthy weight, getting adequate rest, and avoiding diving in cold water if possible. If you have any concerns about your risk factors, consult with a diving physician.
6. Recognising DCS Symptoms
Early recognition of DCS symptoms is crucial for prompt treatment and minimizing potential long-term effects. If you experience any of the following symptoms after diving, seek immediate medical attention and inform the medical professionals that you have been diving.
Joint pain: This is the most common symptom of DCS and typically affects the large joints, such as the shoulders, elbows, hips, and knees.
Skin rash: A mottled or itchy rash may appear on the skin.
Fatigue: Unexplained fatigue or weakness.
Dizziness: Vertigo or a feeling of imbalance.
Headache: A persistent or severe headache.
Numbness or tingling: Numbness or tingling in the extremities.
Paralysis: Weakness or paralysis of the limbs.
Shortness of breath: Difficulty breathing or chest pain.
Confusion: Disorientation or difficulty thinking clearly.
What to Do If You Suspect DCS
Administer oxygen: If available, administer 100% oxygen.
Seek medical attention immediately: Contact emergency medical services and inform them that you suspect DCS.
Provide dive information: Provide the medical professionals with details about your dive profile, including depth, bottom time, ascent rate, and any other relevant information.
Stay hydrated: Drink plenty of fluids.
- Lie down: Avoid standing or walking, as this can worsen symptoms.
By following these tips and staying informed, you can significantly reduce your risk of DCS and enjoy safer, more rewarding diving experiences. Remember to always dive within your limits, plan your dives carefully, and prioritize safety above all else. Consider taking advanced dive courses to improve your skills and knowledge. You can find frequently asked questions on our website.