There are many different types of gauges that are available. There are several types of gauges, including analog, digital and pneumofathometer models. A gauge that is right for you is key to a safe dive. Keeping your gauge calibrated is also vital for decompression safety, especially at altitudes.
Analog gauges
Analog gauges used for gauge diving are useful in helping divers determine the depth of water. You can use them to indicate the depth by turning a needle around a graduated scale. These gauges can be worn on a wrist or integrated into the dive computer. They are less accurate than digital gauges but more reliable than analog. One advantage of using an analog gauge is that you will never run out of batteries.
The gauge's face is easy to read. It has numerical increments of depth ranging from 10'-40' and 20’ to 150'. The gauge has a pressure indicator. It displays pressure ranging from 0 up to 5000psi. The screen displays reserve air and the green screen main air.
Digital models
Many divers desire to dive deep and stay there, but a digital gauge can't be used. The difference in pressure between the gauge and the ambient water can be affected by temperature changes. Fortunately, a mechanical gauge is much safer than an electronic gadget. A gauge not only keeps track of dive time and depth but it also calculates Nitrogen retention and helps prevent decompression illness.
There are two basic types of digital gauge diving computers. The hose technique is the simplest. It uses a hose for connecting the dive computer to a high-pressure port on stage 1. Wireless mode uses an electronic transmitter to communicate with the computer. This type is also available in console and wrist-mounted models.
Pneumofathometers
Pneumofathometers measure the depth of the air supply to a diver. These devices measure the surface pressure of air and indicate the depth either in feet or meters. These devices were used to be mounted on an air pump that provided breathing air for standard diving suits. The air supply was free-flow, with no back-pressure.
Gauge diving is for divers who wish to use a gauge. A gauge should be able to read between 130 and 160 percent the maximum operating pressure of the diving system. For systems that operate at 3,000psi or higher, a gauge with this range will suffice.
Submersible pressure gauges
A submersible pressure gage (SPG), which allows scuba divers keep track of their pressure, is a device used by divers. It displays the current depth as well as the direction that the diver is moving. The SPG connects to the regulator using a high pressure line. This arrangement is useful for divers to avoid getting confused about the location of the gauge and helps prevent it from being lost. A SPG measures the remaining air pressure per square inch. It is used to monitor your air supply while diving.
Scubapro makes an oil-filled analog depth gauge that measures up to 200 feet. It has a Bourdon tube design and is oil-filled. It also comes with a C1 compass, which attaches to the console boot for more versatility. This gauge is ideal to beginners, as it is simple and straightforward to use.
Compass
A compass that is easy-to-read is the best compass to use for gauge diving. The compass should be large enough to be read underwater and be marked with the appropriate markings. Look for a compass bezel with compass headings that are grouped in 30-degree increments. Indicator marks appear every five degrees.
Side view windows should be included in a compass used for gauge diving. This allows the diver to see which direction the compass is pointed. This allows the diver, even in total darkness, to follow the compass's course.