If you think a dive console is simply a collection of gauges, you’re sorely mistaken. The console of the 21st century has become a dive information center, a way to plan dives and track their progress. It not only organizes several pieces of gear, but it should assist in organizing your dive THINKING. A good console will tell you your relative position in space and time. It will tell you where you’ve been, how long you’ve been there, where you should be going, and the time you’ve got left to stay there. Your console is “dive plan central.”
The elements included in a console, and how they are organized (and in some cases interact with one another) will impact greatly on the organization of your dive as it progresses underwater. The elements most often included in consoles today (in order of most important to least) include: pressure gauge, depth gauge, timer (the depth gauge and timer are most often now combined into a dive computer), compass, and thermometer.
In this article, we will look at these elements individually, what’s best, and finally how to combine them for your diving needs. But first, let’s look at a fundamental choice in gauging—digital vs. analog.
DIGITAL VS. ANALOG
In today’s digital world, it is easy to brush off analog as antiquated. Digital is a measurement and display in numbers or digits such as with most LCD displays on today’s dive computers. Analog is a round-face gauge with a needle that moves indicating the measurement desired. Both methods have their strength and weaknesses. Digital is easier to read and understand quickly. In cases with electronics, only a digital display is practical. Analog can be more accurate, particularly at smaller divisions such as shallow depths.
PRESSURE GAUGE
The submersible pressure gauge (SPG) is where the console got started in the late early 1970s. It simply told you, in p.s.i., how much pressure you had left in your tank. A big mental hurdle for beginners, even to this day, is that the amount of air you have left in your tank is not the same as pressure. The amount of air left in a 65 cubic foot at 500 p.s.i. is not the same as a 500 p.s.i. with a 100 cubic foot tank.
Most pressure gauges are not much different than those from the early ’70s. They are analog, a needle and dial, with the guts being a “burdon tube” which is a tube that expands and contracts according to pressure driving the needle and giving you the reading. It is low tech, quite reliable, and accurate.