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Scuba Accidents and Insights

Learning from our own mistakes and miscalculations is a human trait. But, we can also learn from the misfortunes of others and prevent the repetition of similar scenarios.

The factual reports and genuine case studies in this section highlight the tragedies of recent scuba diving accidents and incidents with critical insights to help change future outcomes.

Diving Incident Database: Case Summaries

The Divers Alert Network (DAN) has been maintaining a comprehensive database of diving incidents since 1989.

To begin with, they limited the collection of factual records to accidents and incidents that involved scuba divers.

Currently, DAN's scuba diving accident and incident reports encompass genuine documentation and chronicles about:

The DAN Annual Diving Reports include a vital collection of published analysis. They release the insights and expert conclusions for the benefit of those involved in the scuba diving community.

Furthermore, the featured commentaries and summaries are expressed by professionals in their field. So, divers of all experience levels can use the information to improve their risk management skills and identify safe scuba diving practices.

Note: The main section contains recent news stories about scuba diving and snorkeling activities from around the world, listed chronologically.

Diver's Mouthpiece Became Detached


A diver went diving for four (4) consecutive days. During the second dive of the fourth day the regulator mouthpiece became completely separated from the second stage of the primary regulator.

Scuba Incident Report

The diver was enjoying a diving liveaboard trip and experiencing near perfect conditions. The water was a balmy 29° Celsius (81 Fahrenheit) and the seas were calm during the four days of island hopping. There was almost no noticeable current.

Scuba Incident: Diver's Mouthpiece Became DetachedThe incident happened as the diver carried out the second dive of the fourth day.

Within ten minutes of being underwater, the mouthpiece became completely detached from the primary regulator (e.g. the plastic component of the second stage).

After a few nervous moments, the diver knew there was a problem as they saw the main part of their primary floating in the water in front of them.

The diver reported swallowing at least three gulps of sea water before switching to their backup regulator (called an octopus).

After taking some recovery breaths they safely ended the dive.

The incident report states that the regulator set was less than two (2) years old. But, it seems the plastic zip tie that holds the mouthpiece in place came loose during one of the previous dives.

Professional Evaluation

In this situation, clear communication with dive buddies is vital. The diver handled the situation with some calmness and they called off the dive without delay to fix the issue.

All divers need to check their equipment before entering the water - including their regulator mouthpieces.

In fact, they could have continued breathing from the open section of the primary (without the plastic or rubber gum shield). But, deploying the scuba octopus backup regulator in scuba emergencies such as this was the better response.

What Did We Learn Here?

First, never underestimate the importance of having your diving equipment serviced prior to the start of a diving season. You can become a PADI® Equipment Specialist and save money by doing it yourself.

In general, the manufacturer's recommended frequency for servicing scuba regulators is once a year (or a set number of dives).

Some divers choose to buy custom mouthpieces for their breathing equipment. If so, it's a simple task to exchange a standard piece for your chosen size and colour.

Beginners tend to bite down too hard and loosen the connection. Thus, you must make sure you secure the mouthpiece in the proper manner - using a strong zip tie.

Finally, dive gear should be streamlined and regulator hoses should be a comfortable length. Remember, if you are wearing scuba accessory add-ons, they can become loose if there is excessive twisting or tugging underwater.

An Underwater Altercation


A fight occurred between a dive guide and another diver while they were underwater. Another dive group saw the event take place while they were conducting a drift dive in deep water.

Diver's Incident Report

It was one of those beautiful days that we often dream about for a scuba dive. The group were undertaking a fun excursion with hopes of seeing a range of different sea-life species, and maybe a shark or two.

After making a normal descent, two groups positioned themselves along the edge of the reef. Following on, the dive guide also found a suitable area to settle and promptly hooked into the reef.

Scuba Incident: An Underwater AltercationAs they looked up, they witnessed one of the divers swim over and, without any clear warning, punch the guide in the face.

After the initial blow, they saw the attacker grab the guide and rip off their mask and regulator.

Unsure of how to handle the situation they had just seen, the buddy pair decided to end the dive and ascend to the surface.

It appears the attacker continued with the underwater altercation and inflated the guide's buoyancy device - resulting in a rapid ascent. The guide responded by grabbing hold of the assailant and they both shot up together.

Here's the thing:

When everyone got back on the boat, no one seemed to have sustained any serious injuries. But, they did manage to establish a motive for the attack.

The dive guide had secured his place on the reef and communicated his intent to the rest of the group. But, the attacker seemed unhappy about it and got too close for comfort. A fight broke out after the dive guide pushed the other diver out of the way.

Expert's Review

Scuba divers fighting underwater is not commonplace, but it happens! The diver who submitted a diving incident report to DAN also stated they were shocked by the severity of the brawl and not sure what they should do.

Often, stress and nervous emotion are the root causes of underwater squabbles. Scuba diving is seen as a non-contact sport, and there is no room for violence in the industry.

Scuba diving accidents and incidents such as this one can easily end up having a fatal outcome. The divers who aborted their dive helped to reduce further escalation and the potential for a panicked response.

What Did We Learn Here?

So, the question you may be asking is what should you do if someone attacks you underwater or you are the victim in a fight?

In simple terms, it is usually better to treat an aggressor as if they were a panicked diver (e.g. diversion tactics in scuba rescue training).

How does that work?

Another section contains more information about diving emergencies and the best tow to use while wearing scuba gear. But, the following steps come from the skills you learn in the PADI® Rescue Diver course:

  1. Whenever possible, use physical force to try and push the attacker away from you.
  2. You may also be able to duck down below them so you can get away from their clutch.
  3. Always face the diver (do not turn your back on them).
  4. Signal for help as soon as possible using devices that make a noise underwater (e.g. a rattle, a tank banger).
  5. End the dive without delay and in a safe manner.

So, what should you do if you are witnessing scuba divers fighting underwater? It's best not to interfere or try to break up the fight.

Most divers carry knives. Even though they may not be carrying the best diving knife available, situations like these can soon escalate.

Instead, wait for the tussle to end and then you may be able to assist any victims. Plus, there may be lost equipment that you can retrieve in case there will be a legal investigation.

Once the confrontation has finished, you should consider whether you (and your buddy) are comfortable to continue with the dive. If not, go ahead and surface in the usual, safe manner. In some cases, it is ethical and prudent to inform the dive operator about any untoward events that you witnessed.

Important: Being trained in emergency first aid means you're prepared to assist with medical care. Also, some dive operators will insist on you providing a statement for their incident report. DAN also asks for voluntary submissions of scuba accidents and incidents via their Diving Incident Reporting System (DIRS).

The Nasty Taste of Caustic Cocktail


This incident involved an assisted diver who was diving with friends and using a closed-circuit rebreather (CCR).

The question is... was poor communication with the boat crew to blame for a regular recreational tech dive to end badly?

Diving Incident Report

The diver is a disabled veteran (who dives with assistance) and has a lot of experience with their CCR unit. But, the new crew on the vessel he was diving on were unfamiliar and untrained for handling this type of specialised equipment.

After explaining about their assistance requirements to the crew, the diver completed a pre-dive checklist and pre-breathe obligation.

Here's where things went wrong:

It was clear the hoses were dragging along the boat when the new crew member handed the rebreather to the disabled diver in the water. Even so, he made the final checks and the group started their descent for the dive.

On the way down, at around ten metres, there were some obvious and abnormal breathing issues and they decided to end the dive. The diver who chose to make an incident report to DAN states they inhaled a bad case of caustic cocktail.

After getting back onboard, the symptoms included not being able to talk for half an hour. They also had a burning throat, which lasted for a few days.

Despite not seeking medical attention, the affected diver refrained from any scuba activities for the next six days. They also had their equipment serviced.

Even though it looks like the hose came unattached at some point, it took a deep submersion for the hose to fill with water.

Professional Evaluation

It is important to pack rebreather units with a scrubber material, such as soda lime (a mixture of sodium hydroxide and calcium hydroxide). The scrubber material removes carbon dioxide from the diver's exhaled gas.

But, if a lot of water mixes with the scrubber material it produces a chemical reaction. In turn, this mixture creates concentrated caustic soda, often referred to as 'caustic cocktail'.

Is it dangerous?

Caustic soda can be dangerous if you inhale or ingest it (swallowing it can be fatal). That's why performing pre-dive checklists for rebreathers is an essential task.

There are several ways for water to enter the canister that houses the scrubbing material. But, some of the most common causes will be:

  • Disconnection
  • Failing to close the breathing loop
  • Leakage

Even though the rebreather diver reported carrying out a checklist before the dive, there was no mention about any untoward or abnormal findings in his records.

Nonetheless, calling the dive at the first hint of a problem avoided the need for emergency treatment or a worsening incident.

What Did We Learn Here?

There are several ways to treat the ingestion of caustic soda. You should try to flush it with water as soon as possible. You can use seawater if you don't have access to freshwater.

The primary aim is to reduce the contact time for the caustic soda. So, flushing with freshwater also helps to dilute any residual solution.

Unfortunately, not all crew members who work on dive charters are properly trained how to handle scuba equipment. Even worse, very few boat staff have appropriate first aid training (e.g. EFR Certification).

Related Information and Help Guides

Important: Divers can report a scuba incident to DAN about a near miss or an event that caused personal injury. Published case reports do not identify any individuals who volunteer their story.

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