Hand signs, our language underwater.

In order to really work as a team underwater, we need to have hand signs to communicate.

The most important about the hand signs is that they must be simple, short and if it’s possible that it can be executed with only one hand. The signs here presented were born in cave diving, an exigent environment without space for misunderstandings.

The group that has been given to the signs is just to have some order and facilitate the study, in no case means that the signs cannot be used in a different context.


There are several ways to express numbers underwater, some requires the use of both hands, the technique here presented in the next video uses only one hand to indicate a digit of a number, that is to say if we want to say the number 230 we must signal the digits two three zero.

As mentioned before this technique were born in cave diving and then was adopted for the technical diving, many people associate the way to say numbers with technical diving, but there is no reason why the way to say numbers cannot be used outside the technical or cave diving.

This technique presents the following advantages over the techniques with two hands:

  • It’s easy to execute with only one hand in total darkness, only the hand that is doing the signal must be illuminated.
  • When there is something in one hand like a photographic camera we can signal the numbers with only one hand.
  • If we are in a strong current and we are holding from a line, we can use our free hand for communication.

Problems and Doubts


Decompression or safety stop

Command Signs

The command signs are called this way because requires that the other diver repeats the signs in order to give a confirmation, there are other signs that in order to avoid confusion it’s better to use them as command signs.

More Signs

Example of Sentences