Underwater Dangers II : A Diver’s Guide to Environmental Hazards
Written by Urval Patel, September 2024.
Scuba diving offers a gateway to the ocean’s spectacular beauty, but it also introduces divers to a variety of environmental hazards. These hazards, which are primarily influenced by the natural conditions of the water and surrounding environment, can pose significant risks if not properly understood and managed.
This article (one in a series of articles focusing on ‘underwater dangers’) explores the key environmental hazards that divers may encounter and provides essential tips on how to handle them safely.
Now before we move on – if you are interested in our previous article about Underwater Dangers – A Diver’s Guide to Marine Life Hazard, you can click and read here! All good? Let’s look into this month’s instalment on Environmental Hazards.
1. Strong Currents and Surge
Ocean currents can be unpredictable, and even experienced divers can face challenges if they are caught in strong or fast-moving water. Currents can range from gentle drifts to powerful surges, which can pull divers off course or prevent them from safely returning to the boat or shore.
Rip Currents: These are strong, narrow currents that flow away from the shore. If caught in one, divers may be pulled far out into deeper waters.
Surge: This is a back-and-forth movement of water typically caused by waves. Surge is more common near shorelines and in shallow areas. It can push divers into rocks, reefs, or other underwater structures.
Down Currents: A current that flows downward, which can be disorienting or dangerous if a diver cannot ascend quickly enough.
Prevention and Safety Tips:
- Before entering the water, understand the direction and strength of currents in the area. Read up about tide timing and direction to avoid being caught in a surprise.
- If caught in a strong current, swim parallel to the shore or at a 45-degree angle to the current to escape its pull, rather than swimming directly against it.
- Use a dive flag or marker buoy to help boat operators locate you if you’re carried off course by currents. You can easily purchase a surface marker buoy from Flow to use for all your dives.
2. Poor Visibility
Visibility underwater can change rapidly depending on weather conditions, water quality, and the environment. Poor visibility can disorient divers, increase the risk of separation from dive buddies, and make it difficult to avoid hazards like sharp coral, rocks, or marine life.
Causes of Poor Visibility:
Sediment: Sand or silt stirred up from the ocean floor, especially in shallow areas.
Plankton Blooms: An abundance of plankton in the water can reduce visibility significantly.
Weather Conditions: Storms or heavy rainfall can churn up the water and reduce visibility, making dives more challenging.
Prevention and Safety Tips:
- Always carry a dive light when diving in low-visibility conditions to enhance your ability to see and be seen.
- Stick close to your dive buddy and establish frequent communication signals. Use a reel if required.
- Practice proper buoyancy control to avoid disturbing sediment and further reducing visibility. Flow offers a buoyancy workshop to help perfect your buoyancy through proper breathing and finning techniques.
3. Extreme Water Temperatures
Water temperature plays a crucial role in diver safety. Diving in water that is too cold can lead to hypothermia, while excessively warm waters may increase the risk of dehydration, overheating, or heat exhaustion.
Cold Water: Even with a wetsuit or drysuit, prolonged exposure to cold water can result in hypothermia, which affects the body’s core temperature.
Warm Water: While warm water may seem safer, it can lead to dehydration and an increased risk of decompression sickness if divers overexert themselves.
Prevention and Safety Tips:
- Always wear appropriate thermal protection for the dive location.
- In cold water, consider a thicker wetsuit or drysuit. Take breaks between dives to allow your body to rewarm or cool down, depending on the temperature.
- Stay hydrated, especially in warm water, to prevent dehydration during long dives.
4. Tides and Waves
Tidal changes can significantly impact dive conditions, particularly near shorelines. Changing tides can alter the depth, current strength, and visibility of a dive site, while waves can make entering or exiting the water more dangerous.
Tides: Tidal currents can pull divers in different directions, depending on whether the tide is coming in or going out. High tides generally offer better visibility and calmer conditions, while low tides can expose more hazards like sharp rocks or marine life.
Waves: Large waves, especially near shorelines or shallow areas, can make it difficult to maintain balance when entering or exiting the water. Waves can also stir up sediment, reducing visibility.
Prevention and Safety Tips:
- Plan your dive according to the tide schedule and understand how it may impact the dive site.
- Enter and exit the water during calm periods and avoid diving in areas where waves are too strong for safe movement.
- Watch the water for patterns in wave breaks and time your entry accordingly.
5. Weather Conditions
Weather can change rapidly, and unpredictable weather patterns can turn a safe dive into a hazardous one. Strong winds, storms, and heavy rain can increase wave height, cause poor visibility, and even create dangerous currents.
Prevention and Safety Tips:
- Always check the weather forecast before diving. Avoid diving in storms, high winds, or heavy rain conditions.
- Plan to dive in areas with natural shelters, such as bays or coves, to reduce exposure to wind and waves.
- If you are caught in a storm while diving, stay calm and follow your dive guide or instructor’s instructions to ensure a safe exit.
6. Underwater Topography and Entrapment
The underwater landscape can be both fascinating and dangerous. Wrecks, caves, and underwater structures may attract divers but also pose risks of entrapment or injury.
Wreck Diving: Wrecks can have sharp edges, and unstable structures may collapse, trapping divers inside. Additionally, poor visibility within wrecks can increase the chances of getting lost.
Cave Diving: Cave diving is a high-risk activity due to the confined space and complexity of the environment. Entrapment or becoming disoriented in a cave is a serious hazard.
Prevention and Safety Tips:
- Only dive in caves or wrecks if you are trained and certified for these environments. You can get certified for wreck diving with Flow, where you will be taught responsible wreck diving practices such as how to safely navigate wrecks and proper finning to avoid kicking up silts.
- Always carry a dive light and safety equipment, such as reels or lines, to help navigate confined or low-visibility areas.
- Stay close to the entrance or exit points and avoid penetrating too far into wrecks or caves unless you have the appropriate training.
7. Ghost Nets:
Ghost nets are abandoned, lost, or discarded fishing nets that continue to drift through the ocean, posing a serious hazard to marine life and divers alike. These nets can become entangled in reefs, rocks, or other underwater structures, creating dangerous obstacles for divers.
Entanglement Risk: Divers can accidentally become trapped in ghost nets, especially in areas with poor visibility or strong currents. Entanglement can lead to panic, limited mobility, and, in severe cases, drowning if the diver cannot free themselves quickly.
Sharp Edges and Debris: Ghost nets may contain sharp hooks, lines, or other debris, which can cause injuries like cuts or scrapes, further complicating a diver’s ability to navigate safely
Prevention and Safety Tips:
- Carry a cutting tool: Always bring a dive knife or line cutter when diving in areas where ghost nets may be present. This can help you quickly free yourself in case of entanglement.
- Maintain situational awareness: Stay vigilant during your dive and keep an eye out for any signs of ghost nets or other debris. Avoid swimming through areas with poor visibility or where ghost nets are commonly found.
- Dive with a buddy: Diving with a buddy ensures that you have assistance if you become entangled. A dive buddy can help free you and signal for help if needed.
Conclusion
Diving into the wonders of the underwater world can be an unforgettable experience, but it requires knowledge and respect for the environment. Environmental hazards like strong currents, poor visibility, extreme temperatures, and marine life can pose risks to divers who are unprepared. By understanding these hazards and taking the necessary precautions, divers can safely explore the depths of the ocean while minimizing potential dangers. A well-informed diver is a safer diver, and proper planning and awareness are key to avoiding environmental risks during a dive.
Perhaps it’s time for you to level up and take up the challenge of becoming a Rescue Diver to ensure that you are always ready to attend to possible issues be it for yourself or for your buddy! Feel free to speak to us or email to learn more about this!