The Ontario Underwater Council thought this might be a timely reminder as we enter 2021. As a community, we continue to strive for what we believe to be safe diving practices. Here we offer six safety tips based on a DAN report.

DAN conducted root cause analysis on nearly 1,000 diving fatalities and published triggers and disabling agents:


  • 41% Insufficient gas
  • 20% Entrapment
  • 15% Equipment problems
  • 10% Rough water
  • 7% Trauma
  • 5% Buoyancy
  • 2% Inappropriate gas

Disabling Agents

  • 55% Emergency ascent
  • 27% Insufficient gas
  • 13% Buoyancy trouble
  • 3% Inappropriate gas
  • 2% Equipment Problem

Gas Analysis

Although inappropriate gas represents a very small percentage of preventable triggers, a simple gas analysis on the day of the dive is the best defense for all divers. No matter if someone is breathing Air, Nitrox (EANx) or Trimix, it is comforting to know the content of a dive buddy’s tank in case there is a need to share breathing gas. It is best to start with our own tanks – a proper gas analysis and labeling to reveal the content, and to make sure everyone in the team is doing the same. No agency prohibits the use of gas analyzers in open water training, yet since it is beyond the minimum training standards set by the RSTC, it is left out by many training agencies. In open water training, students develop trust in their instructors or shop(s) when filling tanks and continue to trust any professional in their dive career to fill their tanks with air as they request. Human beings are fallible creatures, grabbing the wrong dive cylinder by mistake, filling an air tank with something other than air, moisture in a steel cylinder causing rust potentially depleting the amount of O2, the list goes on and on. Procure an O2 analyzer and speak to your instructor about learning how to use this piece of life saving equipment to protect yourself and your dive buddy. YES, even for those who dive air exclusively!

Gas Management

In contrast to inappropriate gas, running out of gas triggered almost half of the fatalities studied. It is heart-breaking to learn that nearly 400 of those divers might have survived had they only correctly managed their breathing gas supply. There are divers who unfortunately do not pay attention to their submersible pressure gauges (SPGs) or air integrated (AI) dive computers at all. Most divers, however, do monitor their gas supply, but may not be managing it as safely as possible. Those who are properly trained in gas management would not hesitate to give up a few minutes of bottom time in an effort to maintain sufficient gas supply for two divers sharing while ascending safely if needed. HINT: They are NOT the ones who routinely surface with empty cylinders.


While most think of buoyancy as the ability to stay in the water column with minimal effort, we often forget how we get there. It starts with having a balanced rig – not carrying excess weight so we can surface with ease with a BC failure, but carrying enough so we can maintain control during a shallower stop with nearly empty tanks (e.g. 3m/10’ with 40bar/500psi). With changing thermal protection (3/5/7/14mm wetsuits or 200/400/600gr undergarment), fresh/salt water or by gaining significant weight due to a lack of regular exercise, the amount of lead weight that we carry may vary. Feel free to reach out to your instructor or local dive shop about a checkout dive before conducting more challenging dives. Pay attention to how other divers move underwater – anyone can spot a diver with good buoyancy. You might even want to strike up a conversation and ask for some advice or tips. They would probably be happy to help.


Proper maintenance can ensure reliability and longevity of your investment in scuba equipment. It is also some of the best insurance for staying safe while diving. Regular user maintenance and pre- and post-dive care is critical between the manufacturer’s recommended visits to a service centre. Invest time in reading and learning about the manufacturers’ recommendations for care and maintenance of your specific equipment. When diving, focus on streamlining your equipment to reduce your profile in the water (such as not having dangling gear) to avoid entanglement. You may be surprised to see your gas last longer. Ask someone with a camera to capture a few frames while you are diving for some learning opportunities.

Due to travel restrictions, many cold-water-trained warm water divers are learning how to handle the colder weather. Speak to your local dive shop about servicing equipment that suits your diving needs and is suitable for cold water. Join local clubs or reach out to divers and groups who conduct cold water dives on a regular basis. Even the best equipment cannot replace proper training and experience in a new or more challenging environment with special considerations. Ice diving is a gear intensive activity. It calls for mission specific equipment, training, surface support, a winter diving protocol, and an evacuation plan that can change in a pinch due to weather and surface conditions. Slips, trips and falls on snow or ice covered surfaces potentially causing traumatic injury can be prevented by carefully choosing parking spots and entry points. This is often a team responsibility and we should try to look out for each other throughout our experience.


“Anyone can call a dive at any time for any reason” is far from reality. Many divers hesitate to call a dive because of embarrassment, peer pressure, investment or when trying to achieve a goal. Psychological comfort is often what divers need to make sound decisions as they are trained. This is the reason we typically do not pick dive buddies lightly. A regular dive buddy is often someone whom we want to share our experiences with, offers psychological comfort, and most importantly, someone in whom we trust our lives. If we focus on the latter, the dive team should not end with the choice of whom we dive with underwater. The dive team would easily extend to the surface / shore support, tenders, boat crew, and any shop we might choose. Each party contributes to achieving the best possible outcome of a safe and successful diving excursion that we divers choose to undertake. As divers, we understand the underwater world is a beautiful yet potentially lethal environment and we are on life support equipment. We try to apply our knowledge attained through education while gaining experience. Psychological comfort enables divers to feel safe when calling a dive anytime for any reason.

Fitness to Dive

Fitness and readiness to dive is paramount to dive safety. General fitness is an essential part of being a healthy individual and the foundation of a good diver. Fit individuals are more comfortable encountering physical stress and are more likely to effectively manage strenuous situations like rough water. However, someone can be in excellent physical condition but lacks comfort in the water. Divers who are physically fit but not particularly comfortable swimming should invest training time to increase competency in swimming. A few sessions with a good swimming coach will have a significant impact on technique and endurance, leaving the diver the ability to maintain cardio fitness while improving in water comfort.

A non-smoking diver who exercises and swims several times a week, and maintains a nutritious, well balanced diet, will still need an important component of diving fitness – state of mind to perform a planned dive. The ability to manage and evaluate pre-dive stress, and knowing when to call a dive before or during a dive are all important aspects of readiness.

In Summary

We feel the safety tips offered will cover the majority of the leading triggers published by DAN in this study and encourage divers to exercise caution when diving. More divers will return to the sport after travel restrictions and lockdowns are lifted, and it is recommended that we take a progressive approach. Physical and cardio conditioning, aquatic comfort, and diving in similar conditions to training are considered conservative approaches. The OUC wishes everyone safe and enjoyable dives!

Corey Philips from Ontario Diving ( published an article with useful tips about Winter Diving: