There are many kinds of gauges. There are three types of gauges available: 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
Analog gauges for gauge diving can help divers understand the depth in 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 advantage of an analog gauge over digital is the fact that you never run out.
The gauge's front is simple to read. The gauge has numerical increments that range from 10' to 40’ and 20' up to 150'. The gauge also features a pressure gauge. It displays pressure from 0 to 5000 psi. The red screen is reserved air while the green screen is main air.
Digital models
Many divers desire to dive deep and stay there, but a digital gauge can't be used. Temperature fluctuations can alter the pressure difference between your gauge and the surrounding water. A mechanical gauge is safer than an electronic one. In addition to keeping track of your dive time and depth, the gauge will calculate your Nitrogen retention and help prevent decompression illness.
There are two main types of digital gauge diving computer. The hose approach is simple and uses a pipe to connect the diver's computer to the high pressure port at the top of the first stage. The wireless mode connects to the dive computer using an electronic transmitter attached at the first stage. This type is also available in console and wrist-mounted models.
Pneumofathometers
Pneumofathometers are devices used to gauge the depth of air supplied to a diver. These devices measure the air pressure near the surface and then display the depth in feet (or metres). These devices were originally mounted on a hand-cranked pump that supplied breathing oxygen to the standard diving suit. The air supply was free-flow, with no back-pressure.
A gauge should have a range between 130 and 160 percent of the maximum operating pressure for gauge diving. This range is sufficient for systems operating at 3,000 psi and more.
Submersible pressure gauges
A submersible pressure gauge (SPG) is a device that allows scuba divers to keep track of their air pressure. It can display current depth and indicate the direction in which the diver is moving. An SPG is typically attached to the regulator by a high-pressure line. This arrangement helps the diver avoid confusion and keeps the gauge from getting lost. The SPG indicates the remaining air pressure, in pounds per sq inch. It can be used for air supply monitoring while diving.
Scubapro's oil-filled analog depth meter features a Bourdon Tube design. It measures to a depth 200 feet. The console boot can also be attached to it with the C1 compass. Because it is easy to use, this gauge is ideal for beginners.
Compass
A compass that is easy-to-read is the best compass to use for gauge diving. It should have adequate markings to suit your needs and be large enough to be readable underwater. Look for a compass bezel with compass headings that are grouped in 30-degree increments. Indicator marks appear every five degrees.
A side view window is an important feature of a compass that allows gauge diving. It lets the diver see the direction in which the compass point. This allows the diver even in complete darkness to follow the course of the compass.