My name is Lars Behnke. I am a full-stack developer and I am Apporiented. As the name gives away, I believe in the mobile-first approach when crafting websites and cross-platform applications. Driven by curiosity and an enthusiasm for state-of-the-art technology I provide software solutions since 1998. And last but not least, I am also husband, father of two, biologist, and dive professional with a deep passion for the marine environment and any activity associated with it.

Scuba Diving Hand Signals

Underwater Communication for Recreational Scuba Divers

Proficiency in underwater communication is not only a vital part of scuba diving training, it also makes diving a much more enjoyable and safer experience. Scuba Diving Hand Signals intends to support beginning recreational scuba divers in learning underwater communication via hand signals. More than 240 commonly used gestures are illustrated and grouped into eight categories:

  • Common signals
  • Problem and emergency signals
  • Training signals
  • Air pressure and number signals
  • Underwater wildlife signals
  • Environment signals
  • Emotion signals
  • Miscellaneous signals

Underwater wildlife signals are supplemented with images of each indicated animal and useful information about its features, distribution, and human interactions.

A quiz option makes learning sign language fun and lets you track your learning progress.


The App is available for iPhone, iPod touch and iPad with iOS 8.0 or newer.



Travelling without a smartphone? Scuba Diving Hand Signals is also available as small, full color paperback book.


Visit Amazon.com, Amazon.co.uk, or your local store.

The book is now available as black & white edition, too. Checkout your US, UK or local Amazon store.

The hand signals are partly available online. Visit divingsignals.org to get an impression of the content.

Support and Service

Scuba Diving Hand Signals attempts to provide a collection of underwater signals used by most divers. However, I am well aware that not all divers use the same signals and chances are that you won't agree with all of the signals presented here. So if you like to see signals added or changed in the next release, drop a note. Your feedback is welcome!