Most modern dive computers have the capability to interface with personal computers and, or mobile devices, which enables the user to download the data from the dive computer for storage and analysis.
Using the software provided by the manufacturer, users are able to view and manipulate their dive data in myriad of ways, as well as generate profiles, curves and diagrams based on their data. A typical graphic, that most dive computer software interfaces provide, is one that displays the following dive parameters: depth, time, breathing rate, cylinder pressure, temperature, descent and ascent rates, and any alarms or warnings that were triggered. Divers that use Nitrox as their breathing gas in conjunction with a Nitrox enabled dive computer will also typically be able to view oxygen partial pressure (PpO2) and CNS and pulmonary oxygen (OTU) loading.
Some integration programs allow users to generate theoretical tissue compartment loading graphs that represent the nitrogen saturation of tissues over the course of the dive and nitrogen elimination during the ascent and surface interval.
Take the necessary time to learn how to navigate the software interface and download the data from your dive computer. Talk to your SNSI Instructor or dive center if you need assistance. They will be more than happy to help. Once you’ve become familiar with the interface, you will be able to analyze your dive data, compare it to other dives and share it with your dive buddies. Some programs even have features that highlight areas of your dive profiles that are outside of the expected results.
Take your time when reviewing your dive data. Pay particular attention to the critical phases of the dive and try to associate the data with what was happening during that point of the dive. For example, did the fast ascent alarm trigger, and if so, try to remember what it was that you did during the dive that caused it. Obviously, you ascended faster than the computer’s recommended rate, but why? Did something happen? Did you have trouble with your deflation mechanism? Associating these types of events with specific activities during the dive will help you determine where you can improve your techniques and implement different procedures to avoid ascending too fast on future dives.
Erratic dive profiles in your data are indicative of poor buoyancy control. Take the time to evaluate what it was that happened during that part of the dive that caused this profile and take corrective actions. Often, erratic dive profiles are the result of stress or anxiety while swimming along a wreck or wall, or in a current. Whatever the cause, it should be addressed and corrected as this type of profile increases the risk of DCS.
When comparing your data with your dive buddy’s, you may find it hard to believe that your dive profiles and general dive data are so different — especially when you are convinced that you and your buddy remained side by side during the entire dive. When reviewing the data from the two computers, differences in depth, descent and ascent rates, and respiratory rates will be clear. Such differences reinforce why divers should always use their own computer. The data also shows how different computers react differently to the data obtained based on their algorithms.
For example, certain air integrated dive computers modify their decompression algorithm in response to various conditions, such as speed of ascent and respiratory rate. In this scenario, an increase in respiratory rate in combination with a momentary increase in ascent rate may cause the computer to change its algorithm so that it becomes more conservative than his dive partner’s computer.
This is one example, among many, that demonstrates why a dive team ‘s individual computers will provide different information to their respective diver with regard to surface interval times and repetitive dive parameters. It also reinforces, once more, that divers should have and use their own dive computer at all times.
Many programs that the manufactures provide with their computers include dive-planning modules. Using these tools, multi-level dive profiles can be simulated which may include the associated nitrogen curves (absorption and elimination) generated over the course of the dive. This information is useful for understanding what theoretically occurs with nitrogen over the course of a dive and surface interval. And, when extended over a period of days, the total amount of nitrogen loading the simulation theorizes will reinforce how important it is to carefully plan successive dives over consecutive days.
The ability to add information to a dive profile within the software is a wonderful tool that we should all use. This feature allows you to log every dive with the information that is important to you. In many cases, the software will allow you to choose the dive information recorded by the computer, such as depth, time, temperature, air consumption, etc. You will also have the option to enter any additional information that you feel is necessary. Information relevant to the dive such as the name of your dive buddy, dive operator and dive boat, or the name and location of the dive site and what you saw during the dive are all items that you may want to record to complete the record of the dive. Some of the information that the software asks for may seem unnecessary; however, much of it can be very helpful when planning successive dives, which ultimately enables better risk awareness and management.
Dive computers that integrate with a PC or mobile device represent a significant opportunity for everyone involved in the dive industry, including divers and researchers, to extend our knowledge and understanding diving illnesses such as DCS. In fact, there are many initiatives currently in place, in collaboration with dive shops, resorts and cruise ships, to help researchers gather data downloaded from dive computers. The more valid data that researchers have to analyze helps them to identify potential factors that may contribute to DCS.
We’ve dedicated this portion of the SNSI Advanced Open Water Diver course to discussing dive computers and their features and benefits because they represent valuable tools for divers of every skill level. Additionally, we believe that using a dive computer increases the pleasure and enjoyment of diving, which directly supports the SNSI philosophy that diving should be fun.