Risks of Diving
Diving has exposed the public to the many underwater wonders of the world. The beauty of the various kinds of life that is in the deep blue hides the biggest danger of diving. It isn't sharks or boats or anything else that may exist on or in the water. The real danger to divers is Caisson disease, or decompression sickness.
Anyone who goes from a high pressure to low pressure environment can be afflicted by the disease which is also known as the bends. The disease is a result of Henrys law, which in summary states that gas will form bubbles in a fluid when the pressure goes down. In terms of the bends, nitrogen is typically the gas and the blood is the fluid.
When the process occurs gradually, such as in an airplane cabin, the lungs have enough time to remove the gas before the bubbles form. When it occurs quickly, such as in the case of a diver surfacing too fast, it may result in itching skin and rashes, pain in the joints, paralysis and potentially death.
How to avoid the bends
To prevent the bends, the diver must give the gas a chance to naturally de-gas by ascending slowly. Calculating the time required to come up can be very difficult due to the number of variables that need to be taken into consideration. This is the primary reason as to why dive computers were developed. Timers and sensors are used by dive computers to determine the depth of a diver and the exact duration of the time the diver was at that depth. Calculations are performed by the diving computers in real time and determine the correct process for the diver to ascend without causing the bends.
A dive computer in just about every brand and model is able to sense the exact duration of divers being at certain depths. The diving computer can then estimate the blood gas level of the diver and figure out: the time period in which the diver can surface without having to worry about the bends; the duration of the divers stop at each depth in order to surface safely and the maximum depth the diver can reach amongst other things.
The Diver Interface
The display interface for various forms of divers computer have varying designs, however for the display to be practical it must be clearly read and visible while diving. It should not be cluttered, so the diver does not experience information overload. Further to this, better models of diving computers will be able to give useful information like water temperature, the required decompression time at each depth and dive resurface rate. The top ranging models are able to transmit the entire dive data to a computer for later analysis.
There are also other features that can really set the dive computer ahead of the pack. Once a diver has surfaced, these upper end diving computers will display the time before a diver can board an airplane. That is one of the quickest ways to achieve the bends, is to board an airplane too soon. Other upper end models will also keep track of the air supply available from the diver's tank.
When it comes to buying a dive computer for yourself, you should check to see how much information is provided on the display and whether or not the display is clear and visible, for practicality underwater. You should also check for other features and see what underwater variables are being kept track of in terms of dive quantities. A recommended choice of an excellent diving computer would have to be the Suunto D9.