Six times a year the Scuba STAR Network publishes a short, informal Safety Survey to learn more about various situations experienced by recreational divers. These reports are completely anonymous, and should only take a few minutes of your time to complete. Your inputs will be reviewed and correlated by our staff, and the results posted both here and on DAN's web site for the benefit of our readers. Informal analysis of the results will also be provided in DAN's Alert Diver magazine, and other safety-minded scuba publications.
Click on "Survey Results" to find the results of recent safety surveys!
If you have had an incident involving dive computers, low or out-of-air situations, or other safety-related situations, please use our anonymous Reporting Form to tell us what happened. This data is used to develop our Annual Safety Report.
It can be argued that nothing is as important to a diver as the quality of the air he breathes. Whether it’s compressed air, nitrox, or some exotic mix, and regardless of where the fill is received, it is important that the breathing gas is free from contamination. While breathing gas contamination is considered rare in recreational diving, reports indicate that it occasionally happens.
Perhaps the most common contaminant is water. While we might not consider water to be a physiological problem for the diver, it can take a toll on equipment and cause secondary contamination of the breathing gas. Water can cause oxidation of the cylinder, and the formation of debris from the oxidation process can clog filters and foul regulators.
Perhaps the most insidious contaminant is carbon monoxide. CO is a colorless, odorless gas that binds with the blood’s hemoglobin and prevents oxygen from being carried. Exposure to CO even in very low concentrations can lead to serious injury and even death. On relatively rare occasions, CO is found in breathing gas. Breathing gas contamination can be the result of combustion of other contaminants during the compression process, which overwhelms the filtration process. It can also be caused by improper placement of the compressor inlet, or by improper maintenance of the compressor system.
In some instances, cylinders are “contaminated” with the incorrect breathing gas. This can be caused by incorrect fill procedures or simply by incorrect labeling.
Divers use a variety of means to monitor the quality of their breathing gas. Nitrox divers are taught to independently verify the oxygen content of their fills using electronic sensors. Some divers use electronic or color-change monitors to check their cylinder for CO. One crude gas quality test is the “sniff test,” in which the diver sniffs the air from the cylinder. While the “sniff test” won’t detect CO, divers can sometimes detect odors caused by the combustion of oil or other contaminants in the gas. Some divers rely on the results of independent fill stations’ air quality tests as a measure of confidence in the quality of compressed air produced.
Our July/Aug ‘09 Safety Survey is designed to explore the issues of air quality, including the types of fills that divers receive and the steps they take to verify air quality. Please take a few minutes to complete our safety survey. You’ll be doing your part to improve diver safety.
Note: Some survey questions include the terms ‘occasionally,’ ‘sometimes,’ and ‘on most dives.’ For the purposes of this survey, those terms are defined as follows:
Rarely: less than once in 10 dives Occasionally: 1 or 2 out of 10 dives Sometimes: 3 to 6 out of 10 dives On Most Dives: 7 to 9 out of 10 dives
