There are many different types of gauges that are available. 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
An analog gauge for gauge diving is a tool that allows divers to determine the depth in the water. To indicate the depth, they use a needle that pivots around a graduated gauge. These gauges can be worn around the wrist or integrated into a 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'. The gauge has a pressure indicator. The gauge displays pressures from 0 to 5500 psi. The red screen represents reserve air, while green indicates main air.
Digital models
Divers desire to be able dive deeper and for longer periods of time, but a digital gauge doesn't allow them to do that. Temperature changes can affect the pressure difference between the gauge's water and the ambient. A mechanical gauge is safer than an electronic one. 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 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 of computer can also be found in console and wrist-mounted versions.
Pneumofathometers
Pneumofathometers can be used to measure the depth of air that is supplied to divers. These devices measure air pressure at the surface and then indicate the depth in feet or metres. These devices were previously mounted on the hand-cranked compressor that supplied air to standard diving suits. The air supply was a free-flow system with no backpressure.
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. A gauge with this range would suffice for a system that operates at 3,000 psi or more.
Submersible pressure gauges
A submersible pressure gage (SPG), which allows scuba divers keep track of their pressure, is a device used by divers. It also displays the current depth and the direction 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. The SPG is a gauge that shows you the remaining air pressure in psi. It's useful for monitoring your air supply during diving.
Scubapro offers an oil-filled analog depth gage with a Bourdon tub design. It can measure to depths of up to 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 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.