There are various types of gauges available on the market. There are three main types: Analog, Digital and Pneumofathometer models. You need to find the right gauge for your diving needs. Your gauge must be calibrated at all times, especially when diving at high altitudes.
Analog gauges
Divers can use analog gauges to gauge dive. They are able to measure the depth of the water. You can use them to indicate the depth by turning a needle around a graduated scale. These gauges can either be worn on the wrist or integrated in the dive computer. While the analog gauges are more reliable than digital ones, they may not be as accurate. An analog gauge offers the advantage that you won't run low on batteries.
The gauge's face has been designed to be easy-to-read. It comes with numerical increments of depth that range from 10' - 40' and 20'- 150'. A pressure gauge is also available on the gauge. It can display pressure from 0 - 5000 psi. A red screen means reserve air, and a green screen means main air.
Digital models
Divers often want to dive deep and stay for long periods of time. However, a digital gauge is not able to help them. Temperature changes can cause the difference in pressure between gauge and ambient water to change. A mechanical gauge is safer than an electronic one. The gauge can keep track of your dive time, depth and will also calculate your Nitrogen retention to prevent you from getting decompression sickness.
There are two main types of digital gauge diving computer. The hose technique is the simplest. It uses a hose for connecting the dive computer to a high-pressure port on stage 1. The wireless mode connects to the dive computer using an electronic transmitter attached at the first stage. You can also find this type of diving computer in console or wrist-mounted models.
Pneumofathometers
Pneumofathometers, which are used to gauge the depth to which air is being supplied to a diver, are devices that measure air pressure at the surface. These devices measure surface air pressure and indicate depth in meters or feet. These devices were previously mounted on the hand-cranked compressor that supplied air to standard diving suits. The air supply was free-flow, with no back-pressure.
Divers who want to use gauge diving should purchase a gauge with a range of 130 to 160 percent of the maximum operating pressure of their 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 allows the diver to minimize confusion about where the gauge is located and keeps it from getting lost. A SPG measures the remaining air pressure per square inch. It is used to monitor your air supply while diving.
Scubapro manufactures an oil-filled, analog depth gauge. The Bourdon tube design measures down to 200 feet. It also comes with a C1 compass, which attaches to the console boot for more versatility. This gauge is best suited for beginners because it is simple and easy to use.
Compass
The easiest compass for gauge diving to use is one that is easy enough to read. It should have adequate markings to suit your needs and be large enough to be readable underwater. Look for a compass with a bezel with compass headings grouped in 30-degree increments and indicator marks every five degrees.
Side view windows are important for gauge diving. They allow the diver to see where the compass points. This allows the diver, even in total darkness, to follow the compass's course.