Appendix 3 | Basic Hand Signal Guide

This appendix is purely a bonus since I haven’t been able to publish it anywhere else. I originally organized this material in 2009.

There are some 6000 languages of the world. During our travels as explorers, this is a common barrier to overcome, most commonly in addressing expedition logistics. When working in multilingual teams, this becomes even more complex.

Underwater, as a niche community, we’ve been fortunate to eliminate these communication barriers. While underwater voice and other audible communication devices do exist and are commonplace in specific modes of underwater work and exploration, generally speaking, we rely exclusively on several universal hand signals. These are far from conventional sign language, rather we use simple gestures to communicate series of questions, commands, and values during any given portion of the dive.

As a newbie diver, we all learned a universal, international set of basics for our communication toolset. These included the ‘Are you ok, yes I’m ok’ question and answer, the ‘low on air’, ‘out of air’, ‘let’s go up’, etc. These are the fundamentals and are used on nearly every dive.

In pursuing advanced modes of diving, particularly decompression diving, the information to be communicated is orders of magnitude more complex. For example, we must communicate where and when to make decompression stops, for how long, when to switch gasses, and so on. There have been some isolated factions of divers who have developed signals to address these, and, likewise, there are signals developed for specific types of diving (i.e. cave diving requires some communication that is not required in other modes of diving). At times, when sitting still for instance, it can be more appropriate to simply write down information on a slate, however while on the fly, there has yet to be a universally accepted set of standard hand signal communication for advanced/decompression and exploration caliber diving.

Taking a ‘keep it simple’ approach, two critical elements should be initially agreed upon. First, a numbering system (one through ten), and second, determining what the series of commands and values should look like. If in series, the command itself can even be improvised to some extent and interpreted relatively easily, as many are intuitive.

The most important underlying consideration is that everyone on your team is understanding of an agreed upon set of fundamental hand signals. Certainly, improvisation will be needed from time to time. Keep it simple. Use the command followed by value sequence order and make slow and intentional signals that are clear to see and comprehend.

The Numbers

Here I propose a one through ten numbering system using one hand. In many cases, your second hand will be tied up either managing gear or hanging on a line. Very simply, numbers one through five are flashed using your fingers all faced in an upright fashion. Six through ten are your fingers flashed sideways. The sideways orientation indicates that you are past the number ‘five’. For double digits, you would simply flash both numbers in sequence.

The Command Series

To avoid flapping your hand around like a fish out of water and then getting frustrated that your dive partner has no idea what you are talking about (since it’s always someone else’s fault, right?), a simple but all-inclusive set of commands should be adopted that represent the full spectrum of your diving activities. Here, I demonstrate some basics used in entry-level decompression diving. There may well be commands specific to your diving purpose, and these should be reviewed and rehearsed pre-dive to ensure all divers are familiar with what may be communicated.

In Use

When presenting any combination of commands and values, stick to a logical sequence of the command first followed by the value. In an instance where two commands are in sequence, issue the command-value, command-value. If a command has no value, issue the second command. In essence, your dive partner should follow a series of commands with their respective values until you stop communication. The following are some examples of common sequences: