Do You Know Your Oxygen-Delivery Masks?

By Patty Seery

When a dive accident occurs, prompt action can greatly improve the outcome — if the rescuers respond appropriately. Oxygen administration is a critical element of first aid for dive accidents, but there are several ways to do it. Oxygen units include various delivery systems, including tight-sealing oronasal masks for use with a demand valve or for resuscitation, non-rebreather masks and, possibly, a bag- valve-mask resuscitator, so divers should know the appropriate mask to use in each situation.

Oronasal (resuscitation) Masks

The demand valve with tight-sealing oronasal mask (often referred to as a pocket-style or resuscitation mask) is the most versatile and effective delivery device in most circumstances. When used properly, it can deliver a high percentage of oxygen to breathing, responsive, injured divers. In addition, they can be used to provide oxygen-supplemented ventilations to unresponsive injured divers who are not breathing on their own. This mask can also be used with manually triggered ventilators, which are used to deliver 100% oxygen to divers who are not breathing on their own.

The resuscitation masks have air-cushioned edges that adapt to a variety of face shapes and elastic straps to facilitate a good seal. They also feature oxygen inlets for administering supplemental oxygen when using the mask to provide ventilations to a nonbreathing diver. These masks are reusable, provided they are cleaned, and their one-way valves are replaced.

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When using a resuscitation mask, rescuers should ensure a good seal by using the elastic strap and proper hand positioning. When the injured diver is breathing and responsive, the diver can help with maintaining the mask seal. Rescuers using the mask for CPR or to support inadequate breathing should use two hands to create an effective seal around the entire perimeter of the mask, while, at the same time, tilting the head back and supporting the jaw.

Non-rebreather Masks

Non-rebreather masks are a first-aid option for distressed injured divers who are unable to activate demand valves effectively. These single-use, disposable masks feature an attached reservoir bag that captures the flow of oxygen to the mask to ensure a ready supply. These masks do not conform to faces as effectively as oronasal masks, however, so some oxygen escapes, and some ambient air enters the mask via perimeter gaps. As a result, injured divers using non-rebreather masks receive a lower percentage of oxygen compared with resuscitation masks.

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When using a non-rebreather mask, it is important to tighten the mask’s elastic strap and adjust the nosepiece, but there is not much more rescuers can do to improve the mask’s efficiency.

Non-rebreather masks use a continuous flow of oxygen, which exhausts the oxygen supply more quickly than with other means of oxygen delivery.

Bag Valve Masks

Bag valve masks (BVMs), which are used only on divers who are unable to breathe adequately on their own, are devices that enable rescuers to provide ventilations — with or without supplemental oxygen. They may be disposable or re-usable. Using a BVM is less fatiguing for rescuers than delivering rescue breaths through oronasal masks. These masks come with flexible tubing that connects to continuous-flow outlets of oxygen units. They also have reservoir bags that collect oxygen and are capable of providing high concentrations to injured divers.

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Oxygen delivery using a BVM requires two rescuers: One rescuer maintains the mask seal and the injured diver’s open airway, while the other squeezes the bulb to deliver ventilations. The other primary disadvantage of BVMs is that, like non-rebreather masks, they deplete oxygen supplies relatively quickly.

Regardless of the mask used, a rescuer’s technique affects the concentration of oxygen delivered to the injured diver. To optimise oxygen delivery, be sure to seal the mask to avoid leaks, and continually monitor both the seal and the injured diver. Do not depend on the injured diver to keep the mask secure; their comfort, changes in their level of consciousness and fatigue can compromise mask seal.

Delivery Device Flow Rate: litres per minute (lpm) Inspired Percentage*
Resuscitation (Oronasal) Mask 10 – 15 lpm ≤ 0.45-0.65 (45%-55%)*
Non-rebreather mask 10 – 15 lpm ≤ 0.8 (80%)**
Bag valve mask 15 lpm ≤ 0.9-0.95 (90%-95%)
Demand Valve N/A ≤ 0.9-0.95 (90%-95%)

*May vary with respiratory rate
**Less variation with changes in respiratory rate
+ Delivery percentages vary with equipment and techniques used. This table summarises various oxygen-delivery systems and potential values of inspired oxygen with their use.

Part of being a responsible diver is understanding that different oxygen masks exist, serve a different function, and offer a different level of effectiveness in terms of oxygen delivery. Should you ever require oxygen you will be able to ask that a flowrate be set to the most effective level. Knowing, having, and using the correct mask and correct flowrate is very important in the first aid management of DCI.

Deeper Diving Incidents

The DAN Emergency Hotline recently received two calls for help from technical divers. While all diving carries some degree of risk, tech diving often involves diving deeper and managing higher-risk scenarios. Technical divers in real or simulated overhead situations rely heavily on complicated equipment and extensive training, and it can be harder for them to rectify issues in the water.


The diver in this case was scheduled to perform a solo dive with a run time of four hours. The plan was for the diver to send up his SMB at the dive’s three-hour mark to indicate that he was okay and had arrived at his first deco stop. When the SMB was not launched on time a search commenced. Several local resources, including search-and-rescue and Navy personnel were involved in the search. Sadly, the diver was not located, and after seven days the search was called off.


Chamber operator 2

A hyperbaric facility reported an incident with an Irish diver while they were treating him. The diver, a DAN Member, was doing a week of deep technical dives exploring the wrecks off the north coast of Ireland. The diver had been at a depth of 74m when he experienced an equipment failure that resulted in a failure to deliver gas, which precipitated a rapid unplanned ascent. The diver experienced an immediate onset of DCS symptoms, including full body pain, and was airlifted to the nearest chamber via helicopter.

Following a good response to recompression treatment the diver wanted to fly home just 72 hours after treatment. The treating physician wanted him to extend this preflight surface interval given the severity of the symptoms he experienced, so the diver called DAN to discuss the case further. The DAN representative advised the diver that 72 hours is considered the minimum time period following treatment and it would be wise to wait another few days to fly home.

This diver booked a flight after the call without extending his preflight interval and fortunately returned home without his symptoms worsening. Per DAN advice he sought a follow-up evaluation with a physician back home in Australia for review of symptoms and further treatment.

Review DAN’s Fast Fact about the risks of flying after diving.



It’s important for divers of all levels to assess the degree of risk they face on each dive and determine whether they have the experience, training and equipment to comfortably perform the dive with minimal risk. This is particularly important in technical diving, where equipment failures must frequently be dealt with in the water and returning to the surface for help is not an option. Remember that there is no shame in sitting a dive out if it gives you any hesitation at all — the dive will always be there, and you can come back to give it another shot as soon when you are ready. With deeper and more complex dives, your comfort in the water will affect the safety of your entire team in the water, and your buddy will rely on you to honestly and accurately assess your ability to perform during the dive for your buddy’s safety as well as your own.

Regarding post-treatment flight recommendations, there is some debate about how long divers should wait before flying home after a significant recompression treatment. Because of the statistically insignificant numbers of divers available to study there is little scientific data upon which to base a definitive recommendation. The consensus among many dive-medicine-trained physicians is that a 72-hour wait period before flying is adequate in most situations, but it is still up to the treating physician to recommend what they believe to be most prudent for each patient. Significant DCS symptoms and long or repeated recompression treatments may indicate a need for a longer no-fly period, and it is always in the patient’s best interest to follow the treating physician’s recommendations. For more information on post-treatment no-fly periods, or to have a DAN physician consult with your treating physician, visit

Lessons in Gas Management

A diver, realising it has gotten harder to breathe, checks her air gauge. The display shows “0.” She panics and bolts for the surface.

You may not realise it, but ineffective breathing-gas management while diving is a recurrent problem. During peak season, DAN Medicine speaks with at least two divers every week who have concerns about having made a “rapid ascent” after finding themselves low on or out of breathing gas.

In this post we review three separate incidents involving breathing gas management and discuss why running out of air occurs more frequently than you may realise.


Diver No. 1

A 37-year-old male diver with approximately 30 lifetime dives was doing his first night dive. It was also his first cold-water and first drysuit dive. He was healthy and not taking any medications. The diver descended to 30m, breathing air and using a dive computer. He had some difficulty beginning his descent due to his failure to adjust his weight to compensate for the increased buoyancy of the drysuit. After some time at the bottom he checked his air gauges and found he had less than 20 bar remaining. He signalled to his buddy he was terminating the dive and began to ascend. Because of inexperience, the ascent was not fully controlled, and the diver reported feeling “close to panic.”

Planning sufficient gas reserves to account for unexpected problems helps ensure divers make it back to the surface with gas to spare. Deeper or more challenging dives require greater reserves.

After surfacing, he waited for his buddy, and they swam back to shore. Fortunately, the diver did not experience any symptoms.

Diver No. 2

A 72-year-old male with hundreds of lifetime dives, including several technical dives, was participating in a series of wreck dives with three buddies. He was not known to have any medical conditions or to be taking any medications; he was reportedly in good general health. The first dive was an uneventful wreck dive to 34m for 28 minutes. The second dive was planned as a shallower dive, and the diver’s three buddies descended ahead of him. His body was later found floating on the surface 800m from the initial descent area. One witness reported that the snorkel was in the diver’s mouth when his body was recovered. His weight belt was not in place, and his tank was empty. Circumstances indicated he made a buoyant emergency ascent. His computer recorded a nine-minute dive to 9m. Apparently, each of the four divers used a single tank (per diver) to make both dives. The autopsy findings were consistent with drowning.

Diver No. 3

The diver was a 24-year-old female with approximately 100 lifetime dives. She reported a history of regular exercise and good general health, and she denied taking any medications. Her dives were warm-water ocean dives hunting lobster. The first dive was along a reef structure at a maximum depth of 22m, and some time passed before she located her prey. Trying to capture one lobster required a short chase and raised her respiratory rate. The diver checked her gauge only when she became aware of increased breathing resistance. It displayed “0.” She admitted to panicking and swimming rapidly toward the surface. She failed to jettison her weights or inflate her BCD, which she would have to have done orally because of her empty cylinder. Other divers saw her struggling to keep her head above water and remove the regulator from her mouth. They helped her return to the dive boat, where she had difficulty breathing and coughed up pink, frothy sputum. Crew members provided oxygen and returned to shore, where emergency medical service personnel were waiting. She was transported to the hospital and diagnosed with seawater aspiration. She developed pneumonia and was hospitalised for two weeks, after which she was discharged with no residual problems.

Stuart Cove's Dive Bahamas, New Providence Island, Bahamas.


The reasons behind bad gas management are numerous and varied. The first diver in this case study introduced new environmental factors (a night dive in cold water) and new equipment (a drysuit), and he failed to make adjustments for any of it. As a result, poor buoyancy control, unfamiliar equipment and stressful dive conditions increased his air consumption and reduced the volume in his tank faster than usual. He had an adequate gas supply to make a safe ascent, but his inexperience left him unable to control his ascent rate.

The second diver started his second dive with a practically empty tank, which was either an oversight or a bad decision. He followed his training in making a buoyant emergency ascent, though he clearly ignored it in failing to ensure he had an adequate gas supply at the start of the dive.

The third diver was involved in vigorous and distracting activities. These increased her respirations and sped up the depletion of her gas supply, which she did not monitor carefully. She failed to follow her training by not releasing her weights to increase her buoyancy at the surface.

Exertion, stress, anxiety and environmental factors can all increase respiratory rate. Wearing too much or too little weight can cause divers to work harder, increasing gas consumption. Regardless of factors, however, divers should monitor gas supply frequently and consistently.


When planning a dive, incorporate a breathing-gas limit in the plan. For example, a buddy pair might agree to head back to the exit point when the first diver has used a third or half of his breathing gas (not counting the reserve to be left in the cylinder at the end of the dive). Maintaining buddy contact can make a life or death difference. Safe diving practices and sharpening skills such as buoyancy control reduce the risk of a breathing-gas emergency but do not eliminate it completely.

Proper responses to breathing-gas emergencies rely on experience and skill recall. Establishing and practicing responses are essential; confidence in being able to use an alternate air source provided by a buddy can lead to a much better outcome. Through planning and practice, effective breathing-gas management can become second nature and reduce the likelihood of a diving emergency.

By Marty McCafferty, EMT-P, DMT




Risk and Redundancy

Modern dive computers can give us a wealth of information, but what if yours fails?Equipment redundancy, or having a backup, can help you know your true circumstances and prevent an injury or dangerous situation.

By Doug Stracener

My buddies and I were on a dive boat with several groups of divers who were planning to dive a reef. I was diving with enriched-air nitrox containing 32 percent oxygen (EAN32) to a planned maximum depth of 110 feet (33.5 meters) with two other divers. My primary computer was air integrated (connected to the high-pressure hose and in a console) and several years old.

The dive began as usual: I descended slowly while routinely monitoring my gauges to keep track of depth and remaining gas. As I neared the maximum operating depth (MOD) of my gas, I began to check my depth more frequently to make sure that I did not descend too far. On one of these routine checks I noticed that the depth displayed on my computer had not changed, but the water around me was considerably darker. I stopped the descent to check the computer more carefully, and to my surprise the display dimmed, flashed on and off several times and then died completely. It quickly became apparent that the computer had flooded and was shooting a small stream of bubbles from the case.

Fortunately, I always carry an analog submersible pressure gauge (SPG) and a backup wrist dive computer with me when I dive. This incident shows precisely why you should have redundancy in critical pieces of dive gear.

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Because of the extra equipment I had with me, I was able to quickly check my wrist computer and determine that I was slightly below my working depth of 110 feet but still inside the 130-foot (39.6-meter) MOD for EAN32 when my console computer failed. The analog SPG showed plenty of gas using the rule of thirds. After I notified my buddies, I ascended to 60 feet (18.3 meters) to join another group of divers from the same boat and had a normal 45-minute dive on a beautiful reef.

Afterward, divers aboard the boat had a serious discussion about what could have happened in this situation to a new diver with limited experience using a single air-integrated computer system. The consensus was that new divers may not even be aware of the hazard or the easy solution.

This experience is a great example of having the proper equipment for a planned dive and being prepared with appropriate emergency procedures in case of equipment failure. Dive computers can and will fail, and divers should plan for an inevitable failure. With air-integrated computers, it is especially important to also carry an analog SPG so you know your gas reserves at all times, particularly in the event of a computer failure. Because I also had a redundant dive computer, I was able to continue diving and avoid staying out of the water for 24 hours to revert to diving by tables. I kept myself safe while maximizing my time in the water.

Stay Prepared

Always consider “what if…” before a dive, and have a backup plan. All equipment can fail, and you’ll be better able to handle a situation if you’ve rehearsed an emergency plan than if you try to figure it out in the moment.

Opt for redundancy when possible.

  • Both traditional and air-integrated computers can fail, usually at depth and without warning. A backup SPG and computer can save a dive trip and keep you safe in an emergency situation.

Know your equipment.

  • Study your computer’s manual, and learn the information it contains.
  • Know how to interpret the computer display.
  • Download to your phone a PDF copy of your dive computer owner’s manual. Most manufacturers provide these files for free on their websites. When you cannot figure out how to operate the computer while sitting on a dive boat, having access to the manual can save a dive and help avoid accidents.


© Alert Diver — Q4 Fall 2018


Diagnosis Difficulty: DCI or Something Else

Diver experiences facial numbness and headache: DCI-related or another cause?

In this incident the symptoms that presented could have been attributed to several causes. This is a challenge DAN often faces when a diver calls for help.

A 63-year-old male was on a diving holiday in Papua New Guinea. A call was made to the DAN Diving Emergency Service (DES) Hotline as the diver was experiencing symptoms following two dives he completed the previous day:

  • Dive 1: Depth of 22 meters for a total dive time of 40 minutes, with a surface interval of 2 hours and 30 minutes.
  • Dive 2: Depth of 32 meters for a total dive time of 116 minutes. Long decompression with most of the dive spent at 24 meters.

Both dives were on Nitrox, with no issues noted on either dive.

Twenty minutes after the dive he developed a headache and then numbness around the left eye and around his mouth. The DAN diving doctor performed a neurological assessment over the phone, which the diver completed satisfactorily.

The DAN doctor suggested that the diver go to the local clinic for oxygen first aid. The clinic did not think his condition was DCI-related, so did not give him oxygen treatment. Doctors at a larger hospital advised he was likely to be experiencing DCI.

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The next day the diver’s symptoms progressed to numbness all over the right side of his face and a feeling of facial drooping. DAN staff was concerned that the diver had possibly experienced a stroke but were still not ruling out DCI. While there is a hyperbaric chamber in Port Moresby, DAN recommended the diver be evacuated to Townsville, QLD, for a higher level of care due to the ambiguity of his symptoms.

DAN asked that the diver remain breathing oxygen for as long as possible as the evacuation was organised. Once in Townsville the diver received a single chamber treatment, but there was no change in his symptoms.

After undergoing testing, the diver was diagnosed was Bell’s palsy, which the doctors believed could be coincidentally associated with diving. The diagnosis was reviewed by a neurologist, after which the diver was discharged to return home. Bell’s palsy is paralysis or weakness of the muscles on one side of the face. The exact cause is unknown and most people with Bell’s palsy recover completely with time.

DAN Comment

This incident highlights one of the challenges DAN faces when a call for help is received. The DAN Diving Doctor discusses with the diver:

  • Their dive profiles
  • The symptoms they are experiencing:
    • What they are
    • When they developed
    • Their progression – Have they become worse? Have new symptoms appeared?

Sometimes, from the information provided, it is not clear whether the diver is experiencing DCI and needs to receive recompression or whether the cause is attributed to another cause, such as stroke or a cardiovascular-related incident. The priority in these cases is to get the diver to higher-level care for further assessment and treatment.

Symptoms of DCI Return After Flying

Symptoms Return After Flying: Did the Diver Fly Too Soon?

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In this incident, a diver was evacuated for recompression, but flew home sooner than DAN advised, and unfortunately the symptoms returned and persisted for some time. Could this have been avoided if the diver had delayed his flight home?

The Dives

A 28-year-old dive instructor completed a long 45m dive on mixed gas with decompression. The next day he completed a dive (on air) to 26m for 65 minutes and afterwards noted that he felt more tired than usual.

Symptoms Present

The following day, more than 24 hours after his final dive, he felt an ache/burn in his right shoulder. By the time he called DAN on the next day, he had some altered sensation in his hip and elbow. He had been receiving oxygen first aid for six hours without any significant improvement when he decided to call DAN.

DAN’s Advice

The DAN Diving Emergency Service (DES) doctor was not certain the diver was experiencing DCI based on the information provided. The doctor asked the diver to continue breathing oxygen for a few more hours that evening, take ibuprofen and reassess his condition the following morning.

As the diver was in Timor, where there are no chamber facilities, he would need to be evacuated for treatment if symptoms did not improve.

When DAN spoke to the diver the following day, he advised that he had remained on oxygen for an additional six hours the evening before plus another hour that morning. He thought the ibuprofen relieved the feeling of pressure in his lower back but advised the pain in his right shoulder and the hypersensitivity in his shoulder, arm and chest area were still present, along with the discomfort in his right hip. He was also getting waves of pain in his right elbow and had a stiff right little finger. When he attempted some light activities with his clients he felt short of breath and his breathing was difficult.

Evacuation Required

The DAN doctor advised the diver to see a hyperbaric medicine specialist and that recompression was a possibility. An evacuation to Darwin was impossible — the diver did not have a visa to enter Australia and an emergency visa was not readily available — so the evacuation was directed to Singapore at a cost of USD$34,500.

While waiting for the evacuation the diver breathed oxygen for another three hours and felt much better. In fact, he nearly called DAN to say he was better, but that evening the symptoms returned.


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Once in Singapore, the diver’s evaluation resulted in two recompression treatments. His symptoms mostly resolved but he did express to the doctor that he still had shoulder discomfort after treatment. The doctor believed it was not DCS and discharged him from hospital.

Conflicting ‘Do Not Fly’ Advice

The dive medicine doctor advised the diver not to fly for three days, but DAN advised that this was insufficient and that he should wait at least a week before flying back to Timor given the remoteness of his destination.

The diver ended up flying home four days after treatment and upon his return the diver informed DAN that he was experiencing residual symptoms in his hip, shoulder and elbow.

The DAN doctors advised the diver to continue taking ibuprofen for several days to help with the residual inflammation, remain hydrated and refrain from exercising or going to altitude. The diver’s condition did not deteriorate further, but to his frustration, improvement was very slow.

DAN Comment

While the diver’s symptoms in this case were mild, they were persistent. The diver was evacuated to Singapore and received two treatments, and unfortunately, he did not follow DAN’s advice to avoid flying for at least a week.

In many cases divers are cleared to fly after three days from their final treatment if they remain asymptomatic. This is often fine and many divers following this advice have no further issues — although a small number will.

In this case, the advice by DAN factored in the remoteness of the diver’s location to suggest waiting longer than the doctor’s recommendation. Once the diver flew home to Timor, his symptoms reappearing would put him back in the same situation: experiencing DCI in a location that was not equipped with higher level medical care, including a chamber.

Flying aggravated the diver’s condition, as he likely had residual bubbles in his system, and as such it took a longer time for his persistent symptoms to fully resolve.

This case serves as an important reminder to adhere to the advice of DAN, as our case managers factor in all aspects of a diver’s situation when providing advice.

You can review DAN’s Flying After Diving Guidelines HERE.


Plan Your Dive, Dive Your Plan

dive planning-2.jpgDive Planning

One of the most important things you can do before diving is dive planning. Learn as much as possible in advance about any site you plan to dive.

  • Before you even head out to a site, make sure to investigate currents, depths, marine life, entry and exit points, surfacing techniques, boat traffic, environmental health concerns, etc.
  • Check out what surface support you may need and what local laws or regulations may apply to your planned diving activity.
  • Inform someone who is not coming on your trip what you plan to do and when you expect to be back.
  • Prior to your dive, make sure you and your buddy have the same dive plan. Discuss contingencies should conditions change during your dive. Establish the maximum depth, maximum bottom time and minimum air supply to terminate the dive.
  • Review what you and your buddy would do if you were to become separated, exceed your planned dive or experience an out-of-air emergency or equipment problem underwater. Having these discussions on the surface helps you prepare as a buddy team to manage any situations that may arise while underwater.
  • Review hand signals with your buddy.
  • Conduct a predive test on all your equipment, particularly any rented gear. Use a written or mnemonic checklist to ensure you don’t overlook an essential step. Don’t skip the buddy check.
  • Remember to create an emergency action plan (EAP). This essential tool, which divers are taught how to construct in their advanced training courses, should include what prompts an emergency response, important contact information, the nearest medical facility and the best means of getting there as well as essential first aid equipment.

Dive plans don’t have to be complicated or inflexible, but they are essential for preventing and managing diving incidents.


Buoyancy Control

It’s not surprising that the most common injuries among divers are related to buoyancy issues — barotrauma, uncontrolled ascents, marine life injuries and more can be prevented with some practice and attention to detail.

  • Inefficient buoyancy control can result in descending deeper than planned, altering the intended dive profile and potentially increasing air consumption. Constant adjustments to your buoyancy control device can also affect air consumption.
  • The worst-case scenario is an uncontrolled ascent, which places the diver at risk of a lung overexpansion injury (pulmonary barotrauma) and substantially increases the risk of an arterial gas embolism.
  • Ear injuries are also commonly associated with ineffective buoyancy control. During descent, if you feel uncomfortable pressure in your middle ears or sinuses, you should stop your descent, ascend until the pressure resolves, attempt to equalise and, if successful, continue to descend. If you experience a reverse block on ascent, you should descend a bit and attempt to equalise. These procedures are difficult to execute without proper buoyancy control.
  • Most marine life injuries result from unintentional contact between a diver and the marine life. Proper buoyancy control is essential to protect ourselves and the environment.

The physics of descending and ascending require conscious adjustment based on exposure protection, dive environment and choice of equipment.

Buoyancy Control Begins with Proper Weighting

  • The amount of weight you select should allow you to descend, not make you sink. Predive buoyancy tests are crucial for determining proper weighting.
  • When calculating weight requirements, different exposure suits, dive environments (saltwater vs. freshwater) and cylinder size and composition (steel vs. aluminium) require different amounts of weight to attain proper buoyancy.
  • Your BCD is not an elevator. Be aware of how your BCD responds to addition or venting of small amounts of air.
  • And remember, your buoyancy will change during the dive. On descent your wetsuit compresses, decreasing buoyancy. During the dive, as the gas in your tank is depleted, the tank becomes more buoyant. On ascent, the air in your wetsuit and BCD expands, increasing your buoyancy.

Good buoyancy control enhances your diving and helps you avoid injury. The benefits are definitely worth the investment of time, maintenance and practice.

Never Dive Beyond Your Training

As a diver, you should never stop developing your diving abilities. There is always more to learn —how to dive new environments, how to refine your skills and even how to use new types of equipment. No matter where your diving adventures take you, make sure you are equipped with the proper training.


  • Your certification only qualifies you for the same diving conditions and environment in which you were trained.
  • As you continue your training, slowly extend your diving experiences. California shore diving presents different challenges than Caribbean boat diving — make sure you’re prepared for each new diving environment.
  • Take it easy, and if you’re not having fun or if you don’t feel good about the dive, don’t do it. This is especially important when diving in new conditions such as cold water or limited visibility or when using new equipment.
  • If you feel uncomfortable about a dive, it may because you feel that you’re not ready. Remember, dive your experience, not your “C card.”
  • If you want to begin exploring new environments, seek the training that will prepare you to explore them safely. For instance, if you want to explore the interiors of shipwrecks or enter a cave, enrol in a wreck diving or cave diving course. These unique overhead environments present specific challenges that can be deadly if you are not trained to manage them.

Your Gas Supply

Running out of air is the most common trigger for diving accidents. It seems like a no-brainer, but several factors can affect consumption rate. Be air aware: Monitor your gas supply.

  • Incorporate gas supply into your dive planning. You can only stay under for as long as you have enough gas remaining to do a safe ascent. Don’t forget to save some gas for flotation.
  • Check your gauge regularly.
  • Be aware that exertion, such as when swimming against strong currents, and depth will affect your air consumption.
  • Anxiety or stress can also affect air consumption. Try to maintain normal breathing, but if you do feel anxious, keep a closer eye on your gas supply; it may dwindle more rapidly than usual.

Take Personal Responsibility

Each diver in the dive group shares responsibility for the conduct of the dive. When all divers understand and agree with that premise, the dive group can protect itself from individual and collective harm. Know your personal limits, and take time to examine and evaluate your dive habits. Don’t rely on the experience of other divers in the group. As a certified diver, you are expected to recognise when elements are outside your level of training or comfort zone; it is your responsibility to acknowledge that and voice it. Always remember, anyone can call off a dive at any time. In other words, it’s always OK to say “No.”

We hope these reminders help you get your year off to a safe start and will be carried with you through the year and beyond. Have a great year of diving, and if you need help, DAN is just a phone call away, 24/7: +61-8-8212 9242