Sight Search

Low-Visibility Diving

Cristina Zenato explores a cave in the Channel Islands National Marine Sanctuary. Cave divers carry a minimum of three lights to cover for potential failures. Photo by Jill Heinerth
CREDITS | Text By Frauke Tillmans, Ph.D.

WEATHER, SILTY SEDIMENT, time of day, or water movement are just a few natural factors among the range of possible causes that can influence the visibility at your dive site. Low-visibility diving can be quite enjoyable, but it depends on the circumstances and your comfort level.

Why do people dive in low-visibility environments?

Some divers, such as public safety divers, might have to venture into low-visibility situations. Recreational divers may have no clear water nearby but want to dive regardless. Searching for great treasures, such as blackwater diving for megalodon teeth, is adventurous, even for experienced divers. Some creatures only come out for the critter hunters to see when it is dark or when the sea is a bit more disturbed than is comfortable.

Most of these scenarios are predictable, but low visibility becomes especially tricky when a diver is unprepared. Touching down on a muddy bottom upon entry or one wrong fin stroke or hand movement in a silty, easily disturbed environment can put an end to what visibility you have.

What is the worst thing that could happen?

It can be a fun experience to dive without seeing anything. When you need to rely totally on your ears and hands, you will be surprised by how quickly your body can adjust to the new situation.

A complete loss of orientation, however, can be alarming. If you have little or no experience in poor visibility but must suddenly deal with it, it would not be surprising for panic to set in. Panic is among a diver’s worst enemies and can ultimately lead to death in a rare worst case, but it is something you can overcome through preparation and training.

The most important thing to remember is that if you see that you cannot control the dive conditions and don’t know if you are up for the challenge, call the dive. You can do so before or at any time during the dive.
How can we deal with bad visibility?
Tools: If you know that visibility will be poor when planning a dive, make sure you have the right gear with you and the confidence to use it. This equipment may include underwater lights, a strobe light, a surface marker buoy (SMB), spools, a reel, and a compass.

Lights can help in low visibility, but they can also make it worse in some conditions. If particles and disturbed sediment are abundant in the water, a light will illuminate those particles, which can be bright and make it harder to see where you are going. You might need to angle your light downward rather than straight in front of you and reduce the light intensity. A strobe light is a good option for marking an entry or exit point in low visibility. It might also be a way to mark yourself by illuminating your tank so your buddy can more easily spot you if you get separated.
After a separation incident, buddies are less likely to find a diver dressed in a black suit, hood, mask, gloves, and fins. Bright colors are a safety asset in low visibility. If you lose visual contact with your dive partner, follow your agency’s recommendations. These procedures usually include carefully searching — in this case with all your available senses — for one minute before surfacing to reunite the team. While you search, remember that you are in a 3D environment and cover all directions.

A spool or reel can be useful for safely finding your way back to where you came from if you know how to deploy it and reel it in without making a mess. Cavern or wreck diving classes will teach you how to use a reel or finger spool. You do not have to start cave diving to benefit from the skills an entry-level overhead-environment class can give you. When you expect limited visibility, go over some additional communication signals with your buddy. Signals using light or touch may be the only way to communicate.

Lines: 

Public safety dive teams combat low or no visibility with a tended line, but that is not a valid option for a sport diver without the necessary training. Using lines, however, is a strategy that all divers can employ. A buddy line is an option for two teammates who do not want to get separated. Buddy lines are relatively short ropes — short enough to limit entanglement but not too short to prevent movement — connected to your gear with carabiners or preferably by slipping a loop around your wrist.

Disorientation: 
If you get disoriented — whether it’s being unable to remember the way back to the boat’s downline or trying to use your bubbles to orient yourself to the surface in a silt-out — you should be able to rely on your predive preparation. Research everything about the dive site before getting in the water. Learn where there are points you can reference during your dive; if you are wreck diving, for example, memorize how deep the wreck lies and at what depth the anchor line is attached. Know that you are on the way back when the wall is on your left shoulder and not your right, remember which direction you went from the entry, or use a compass to navigate back.

If you become disoriented during an open-water dive and can’t safely determine which direction is home, make sure you have the means to signal your location to the surface crew. Separation, signaling, and retrieval procedures should be part of every safety briefing. You should be able to safely deploy an SMB for an unplanned ascent. If current is present and you have the opportunity and know how to, you might want to attach the SMB to the wreck or dive site and follow that line up to ensure you do not drift farther away.

Whatever happens, make a safe ascent, and do not violate your ascent or decompression obligations. You can deal with most problems at the surface. In a true emergency that requires a rapid ascent, do it as safely as possible. Don’t ever worry about ditching nonvital equipment if you have to — losing a spool, a double ender, or weights is much less of a problem than being lost at sea.

Mental preparation: 
The most important tool you have in your kit is your brain. Do your homework ahead of time, and mentally go through the dive before getting into the low-visibility situation. Review the safety procedures in detail with your teammates, and make sure everyone knows how to react. If your vision gets restricted, take a couple of sanity breaths, and start thinking about your options and strategy. Knowing that you can safely make it out of a challenging situation will calm you, help prevent panic, and potentially lessen your risk of injuries that could occur with an uncontrolled ascent.

Your comfort zone is entirely about you. Are you comfortable in zero visibility? Will you ever be? What is it about this experience that some people love and want to do again and again? If you have not already dived in low visibility, it’s worth trying at least once with someone who has experience. It’s almost meditative for some divers. If you are still not convinced after trying it, nothing is lost. It will make you appreciate crystal-clear waters even more.

You can prepare for many of these situations by taking specialty courses. You can acquire some skills during the course, while the rest will come with practice and exposure. A limited-visibility or night diving course, a cavern class, or an advanced wreck diving course will prepare you for some scenarios you might not have considered. The skills you learn will work for you in murky water and make you a better overall diver.

© Alert Diver Magazine Q1 2022/ DAN.org

Categories

 2021
immersion and bubble formation 232bar AGE Accident management Accidents Acid reflux Acute ailments Aerobic exercise After anaesthesia Aged divers Air Quality Air exchange centre Air hose failure Air supply Airway control Air Alert Diver Magazine Alternate Airsources use Alternater Air Source Alternative gas mix Altitude changes Altitude diving Altitude sickness Aluminium Oxide Ama divers Amino acids Amos Nachoum Anaerobic Metabolism Animal life Annual renewal Anxiety Apnea Apnoea Aquatic creatures Aquatic life Aquatics and Scuba Diving Archaeology Argonaut octopus Argonauts Argon Arterial Gas Embolisms Arterial gas embolism Arthroscopic surgery Aspirin Audible signals Aurel hygiene Australian Flat backed BCD BHP BLS BWARF Back adjustment Back pain Back treatment Backextensors Badages Bag valve mask Bahamas Balancing Bandaids Barbell back squat Barometric pressure Barotrauma Basic Life Support Batteries Beach entry Becky Kagan Schott Bench press Benign prostate hyperplasia Benzophenones Beth Neale Beyond Standards Bilikiki Tours Biophysics Black Blood flow Blood pressure Blood thinners Blue Desert Blue Wilderness Blue economy Blurred vision Boat safety Boesmans gat Boesmansgat Bone fractures Bouyancy compensators Bouyancy controls Boyle's Law Boyle\'s Law Bradycardia Brain Brandon Cole Breast Cancer Breath Hold Diving Breath hold diver Breath holding Breath hold Breath-hold Breathing Gas Breathing gas contamination Breathing Breathold diving Bright Bank Broken bones Bruising Bubbleformation Buddy Exercise Buddy checks Buoyancy Burnshield CGASA CMAS CO2 COVID-19 Updates COVID-19 COVID CPR Cabin pressure Caissons diseas California Camera equipment Camera settings Cameras Cancer Remission Cancer treatments Cancer Cannabis and diving Cannabis Cape Town Dive Festival Cape Town Dive Sites Cape Town CapeTown Carbon Monoxide Carbon dioxide Cardiac research Cardio health Cardiological Cardiomyopathy Caribbean Carmel Bay Catalina Island Cave diving Cave exploration Cave Challenging Environments Chamber Safety Chamber science Chamber treatment Charging batteries Charles' Law Charles\' Law Charles\\\' Law Charles\\\\\\\' Law Charles\\\\\\\\\\\\\\\' Law Charlie Warland Chemotherapy Chest compressions Children diving Chiropractic Chlorophll Chokka Run Christina Mittermeier Citizen Conservation Citizen sciences Citizen science Cleaning products Closed Circuit Rebreathers Cmmunity partnership Coastal diving Coastalexcursion Cold Water Cold care ColdWater Cold Commercial Fishing Commercial diving Commercial schools Composition Compressed Air Compressed gas Compressor operators Compressors Concussion Congestive heart Faiture Consercation Conservation Photographer Conservation photography Conservation Contact lenses Contaminants Contaminated air Coral Conservation Coral Reefs Coral Restoration Coral bleaching CoralGroupers Corals Core strength Corona virus Coro Costamed Chamber Courtactions Cozumel Cradiac valvular Cristina Mittermeier Crohns disease Crowns Crystal build up Crystallizing hoses Cutaneous decompression Cylinder Ruptures Cylinder capacity Cylinder handwheel Cylinder valves Cylinder weight DAN Courses DAN Profile DAN Researchers DAN medics DAN members DAN report DANTraining DCI DCS Decompressions sickness DCS theories DCS DEMP DM training DNA DReams Dalton's Law Dalton\'s Law Dalton\\\'s Law Dalton\\\\\\\'s Law Dalton\\\\\\\\\\\\\\\'s Law Danel Wenzel Dangerous Marinelife Dauin island David Doubilet Dean's Blue Hole Dean\'s Blue Hole Deco dives Decompression Illness Decompression Sickness Decompression Stress Decompression chamber Decompression illsnes Decompression limits Decompression treatment Decompression Decorator crabs Deep diving Deep water exploration Deepest SCUBA Dive Delayed Offgassing Dental Dever Health Diagnosis Diaphragms Diopter Diseases Disinfection Dive Buddy Dive Chamber Dive Computer Dive Destinations Dive H Dive Industry Dive Instruction Dive Instructor Dive Medical Form Dive Medical Dive Practices Dive Pros Dive Rescue Dive Research Dive Safari Dive Safety Tips Dive South Africa Dive Training Dive Travel Wakatobi Dive Travel Dive accidents Dive buddies Dive computers Dive courses Dive cylinder Aluminium Dive excursions Dive exercise Dive exeriences Dive experience Dive fitness Dive gear Dive heallth Dive health Dive in Africa Dive medicals Dive medicines Dive medicine Dive operators Dive opportunities Dive planning Dive procedures Dive safety 101 Dive safety Dive safe Dive skills Dive staff Dive travels DiveLIVE Diveleader training Diveleaders Diver Health Diver Profile Diver Travel Diver infliencers Diver on surface Diver recall Diverover 50 Divers Alert Diversafety Divesites Diving Divas Diving Kids Diving Programs Diving Trauma Diving career Diving emergencies Diving emergency management Diving fit Diving guidelines Diving injuries Diving suspended Diving Dizziness Dolphins Domestic Donation Doug Perrine Dowels Dr Rob Schneider Drift diving Drysuit diving Drysuit valves Drysuits Dynamic environment Dyperbaric medicines EAPs EAP Ear pressure Ear wax Ears injuries Eco friendly Education Electronic Emergency action planning Emergency decompression Emergency plans Emergency underwater Oxygen Recompression Emergency Endurance Envenomations Enviromental Protection Environmental factors Environmental impact Environmental managment Equalisation Equipment care Equipment failure Equipment inspection Equipment significance Evacuations Evacuation Evaluations Even Breath Exercise Exercising Exhaustion Exposure Protection Extended divetime Extinguisher Extreme treatments Eye injuries FAQ Factor V Leiden Failures FalseBay Diving Fatigue Faulty equipment Female divers Fetus development Filling stations Fillings Fire Coral Fire Safety Firefighting First Aid Equipment First Aid Kit First Aid Trainig First Aid Training First Aid kits First Aid Fish Identification Fish Life Fish Fit to dive Fitness Levels Fitness Training Fitness evaluation Fitness to dive Fitnesstrainng Fitness Flying Focus lights Foundations Fractures Francesca Diaco Francois Burman Fred Buyle Fredive Free Student cover Free diving Free flow Freedive INstructor Freedive Training Freediver Freediving Instructors Freediving performance Freediving Gar Waterman Gas Density Gas consumption Gas laws Gas mixes GasPerformance Gases Gass bubbles Gastoeusophagus Gastric bypass Gastroenterologist Gear Servicing Germs Geyer Bank Giant Kelp Forest Giant Kelp Girls that Scba Gobies Gordon Hiles Great White Sharks Green sea turtle Greenlings Guinness World Record Gutt irritations HBOT HCV HELP HIRA HMLI HMS Britanica Haemorhoid treatment Hand signals Hawaii Hawksbill Hazard Description Hazardous Marine life Hazardous marinelife Head injuries Headaches Health practitioner Heart Attack Heart Health Heart Rate monitor Heart fitness Heart rates Heart rate Heart Heat stress Heliox Helium Hemodynamic Hepatitis C Hepatitus B Hiatal Hernia High Pressure vessels High pressure hoses High temperatures Hip strength Hip surgery Hippocampus History Hole in the heart Hot Humans Hydrate Hydration Hydrogen Hydroids Hydrostatic pressure Hygiene Hyperbaric Chamber Hyperbaric Oxygen Treatments Hyperbaric Oxygen Hyperbaric research Hyperbaric treatment Hyperbarics Hypertension Hypothermia Hypoxia I-52 found INclusivity IdentiFin Imaging Immersion Immine systems In Water Recompression Indemnity form Indian Ocean Indigo SCuba Indonesia Inert gas Infections Infra red Imaging Injections Inner ear Instinct Instruction Instructors Insurance Integrated Physiology International travel International Internship programs Internship Interval training Irritation Irukandji Syndrome Isotta housing Itchy Rash Jellyfish Jill Heinerth Joint pain Junior Open Water Diver KZN South Coast KZN Karen van den Oever Kate Jonker KateJonker Kenya Kidneys Kids scubadiver Komati Springs KwaZulu Natal Labour laws Lake Huron Laryngospasm Lauren Arthur Learning to dive Leatherback Legal Network Legal advice Legislation Lembeh Straights Lenses Leukemis Liability Risks Liability releases Liability Life expectancy Lifestyle Lightroom editing Lionfish Live aboard diving Liveaboard Liver Toxicity Liver diseas Liz Louw Loss of consciousness Lost at sea Low Visability Low blood pressure Low pressure deterioration Low volume masks Lumpsuckers Lung Irritation Lung function Lung injuries Lung squeeze Lung surgery Lung MOD MOzambique diving Macro photography Mafia Island Maintenance Malaria Mammalian Dive Response Mammalian effect Mandarin Fish Marfan syndrome Marine Biology Marine Mega fauna Marine Science Marine Scientists Marine conservation Marine parks Marine plants Marinelife Marinescience Marlin Mask clearing Masks Master scuba diver Maximum operating depth Medical Q Medical emergencies Medical questionaire Medical statement Medicalresearch Medicalstudents Medication Mehgan Heaney-Grier Membership benefits Menopause Menstruation Mermaid Danii Mesophotic Mexico Michael Aw Middle ear pressure Mike Bartick Military front press Misool Resort Raja Ampat Mixed Gas Mono Fins Mooring lines More pressure Motion sickness Motionsickness Mount Kilimanjaro Mozambique Muscle pain Mycobacterium marinum Narcosis National Geographic Nausea Nautilus Ndibranchs Neck pain Neoprene layers Neuro assessments Neurocognitive research Neurological assessments Neuromotor exercises Nichola Bird Nitrogen Narcosis Nitrogen build up Nitrox No Decompression Limits No-decompression limits No-decompression Non-nano zinc oxide Non-rebreather Mask Nondiving related illness Nonrebreather masks Normal Air North Sulawesi Nosebleeds Nudibranchs Nuno Gomes O2 providers O2 servicing O2treatments OOxygen maintenance Ocean Projects Ocean Research Ocean animals Ocean conservation Ocean migrations Ocean pollution Oceangate Octopus Oil contamination Olive Ridley Open Ocean Open water divers Optical focus Oral contraseptives Orbital implants Oronasal mask Osteonecrosis Out and about Out of air Outer ears Outreach Overhead Envirenments Oxygen Administration Oxygen Cylinder Oxygen Units Oxygen deficit Oxygen deicit Oxygen dificiency Oxygen ears Oxygen equipment Oxygen masks Oxygen providers Oxygen supplies Oxygen supply Oxygen systems Oxygen therapy Oxygen P J Prinsloo PADI Freedivers PFI PFO PJP Tech Paper Nautilus Paralysis Parentalsupervision Part 3 Partner Training Patent foramen ovale Pemba Island Peri-peri Divers Perspective Peter Lindholm Philippine Islands Philippines Phillipines Photographers Photography tips Photography Physical Fitness Physioball Physiology Physiotherapy Pills Pilot Whale Pistons Planning Plastic Plimsoll Interface Pneumonia Pneumothorax Poison Pollution Pool Diving Pool chemicals Pool maintenance Pool workout Pools Post-dive Potuguese man-of-war Pre-dive Predive check Pregnancy Pregnant divers Preparation Prepared diver Press Release Preventions ProDive Port Elizabeth Professional rights Provider course Psycological Pulmanologist Pulmonary Barotrauma Pulmonary Bleb Pulmonary Edema Pulmonary Hypertension Pulse Punture wounds Pure Apnea Purge RAID South Africa RCAP REEF Radio communications Range of motion Rashes Rebreather diving Rebreatherdive Rechargeable batteries. Recompression chamber Recompression treatment Recompression Recycle Reef Chcek Reef Conservation Reef Environmental Education Foundation Reef safe Reef surveyors Refractive correction Regal Sea Goddesses Regulator failure Regulators Regulator Remote areas Remote islands Renewable Report incidents Rescue Divers Rescue Procedure Rescue breathing Rescue breaths Rescue skills Rescue skill Rescue training Rescue Research Resume diving Return To Diving Return to diving Risk Assessments Risk assesments Risk assessment Risk elements Risk management Risks of Seizures Roatan Marine Park Roatan SABS 019 SMB SafariLive Safety Concerns Safety Gear Safety Stop Safety in Air Safety SaherSafe Barrier Salish Seas Salty Wanderer Sanitising Sara Andreotti Sardine Run Sargassum sea Saturation Diving Save our seas Schrimps Science Scoliosis Scombroid Poisoning Scorpion Fish Scuba Air Quality Scuba Guru Scuba Injury Scuba Instructor Scuba children Scuba divers Scuba dive Scuba education Scuba health Scubalearners Scubalife Sea Horses Sea Turtles Sea slugs Seagrass Sealife Seasickness Seaweeds Seaweed Sea Self Rescue Shallow dives Shark Protection Shark Research Shark conservation Shark diving Sharks Shipwrecks Shore entries Shoulder strength Sideplank Signs and Symptoms Silty bottoms Sit-ups Sixgill Sharks Skin Bends Skin outbreak Skin rash Smart phone photography Snells Window Snorkeling Snorkels Social Distancing Sodwana Bay Solomon Islands Sonnier bank South Africa SpareAir Sperm Whales Spinal Bend Spinal bends Spinal cord DCS Spinal dura Spinal pain Spinner dolphins Splits Sports medicine Squeezes Squid Run Stability exercise Standars Statin Mediction Stay Fit Steel Stents Step ups Stephen Frink Stepping up Stockton Rush Stonetown Strobe Lighting Stroke Submerge tech Submerged Sudafed Sulawesi Sun protection Sunscreen Supplemental oxygen Surface Marker Buoys Surface supplied Air Surfaced Surgeries Surgery Suspension training Swim Fitness Swimmers health SwimmingIn wateractivities Swimming Symbiosis Symbiosys TRavel safety Tabata protocol Talya Davidoff Tanzania Tattoes Tec Clark Technical Diving Technical divng The Bends The Titanic Wreck The Wild Coast The greatest Shoal The truth Thermal Notions Thermoregulation Thomas Peschak Thunder Bay National Marine Sanctuary Tides Tips and trick Tonga Tooth squeeze Transplants Travel destinations Travel smarter Travel tips Travel Tropical Coastal Management Tunnelling Turks and Caicos Turtles Tweezers Ultrsound Umkomaas Unconsciousness Underground work Underseaa world Underwaater Photos Underwater Photography Underwater Photograper Underwater Photograpgraphy Underwater Photographer Manirelife Underwater Research Underwater critters Underwater floral Gardens Underwater hockey Underwater imaging Underwater photographer Underwater photography Underwater pho Underwater sound Underwatercommunications Underwater University of Stellenbosch Urinary retention. Vacations Vaccines Vagus nerve Valsalva manoeuvers Valve stem seals Vape Vaping Vasopressors Vasvagal Syncope Venting Verna van Schak Virus infections Volatile fuels WWII wrecks War stories Washout treatments Wastewater Watchman device Water Resistance Water Weakness Weigang Xu Weights West Papua Western Cape Diving Wet Lenses Wet diving bell Wetsuit fitting Wetsuites Wetsuits White balance Whitetpped Sharks Wide Angle Photos Wide angles Wildlife park Wildlife Winter Wits Underwater Club Wolf Eels Woman and diving Woman in diving Womans health Woman Women In Diving SA Women and Diving Women in diving Womens Month Womens health Work of Breathing Workout World Deeepst Dive Record World Records Wound dressings Wreck History Wreck divers Wreck dive Wreck diving Wreck exploration Wreckdiving Wrecks Yoga Youth diver Zandile Ndholvu Zanzibar Zoology Zooplankton abrasion absolute pressure acoustic neuroma excision adverse seas air-cushioned alert diver altitude alveolar walls anemia antibiotics anticoagulants antiseptics bandages barodontalgia bent-over barbell rows bioassays biodiversity bloodcells body art breathing air calories burn carbon dioxide toxicity cardiovascular career developments cerebrospinal fluid cervical spine checklist chemo port children child chronic obstructive pulmonary disease clearances closed circuit scuba corrective lenses currents cuts cylinder filling dead lift decompression algorithms decongestants decongestion dehydration dive injuries dive medicing dive ready child dive reflex dive tribe divecomputers diver in distress diver rescue diver training dive diving attraction doctors domestic travel dri-suits drowning dry mucous membranes dry suits dry e-cigarettes ear spaces elearning electrolyte imbalance electroytes emergency action plans emergency assessment emergency training environmentally friendly equalising equalizing exposure injuries eyes fEMAL DIVERS fire rescue fitness Balance fitnes flexible tubing frediving freedivers gas bubble gas poisoning gastric acid gene expression health heartburn histidine hospital humidity immersion and bubble formation immersion pulmonary edema (IPE informal education isopropyl alcohol jaundice join DAN knee laparoscopic surgery longevity lower stress malaise marielife marine pathogens medical issues medical procedures medical risk assesment medications mental challenge mental preparedness micro-organisims micro minor illness mucous membranes multilineage dysplasia myelodysplasia nasal steroids nasal near drowning nematocysts neurological newdivers nitrogen bubbles off-gassed operating theatre operations orthopeadic otitis media outgas pain perforation phillippines phrenic nerve physical challenges pinched nerves plasters pneumoperitoneum polyester-TPU polyether-TPU post dive posture prescription mask preserve prevention proper equalization psychoactive pulmonary barotrauma. pulmonary injury. pulmunary barotrauma radiation rebreather mask rebreathers retinal detachment risk areas safety stops saturation scissors scuba equipment scuba sea goddesses single use sinus infections situationalawarenes smoking snorkeling. spearfishing sterilising stings strength sub-aquatic sunscreen lotion swimmers ears tattoo care tecnical diver thermal protection tissue damage toxicity training trimix unified standards upwelling vision impaired vomiting warmers water quality zinc oxide