Underwater communication signals: the language of divers

Dive signals are a universal language every diver understands anywhere in the world, and they are the lifeline of communication underwater.

Mandatory basic signals

OK signal
The thumb and index finger form a circle while the other three fingers stay up. This signal means you are OK, or are you OK.

Ascent signal
A thumb pointed up means we ascend now, or we must ascend.

Descent signal
A thumb pointed down means we descend, or I want to go deeper.

End-of-dive signal
An open hand with fingers together, moved up and down, means we end the dive and ascend now.

Emergency signals

• Ear problem: a finger pointing to the ear and a pain expression on the face
• Out of air: a horizontal hand drawn across the neck as if cutting
• I need your backup air: a hand pointing to the mouth repeatedly

Signaling with a light at night

• A circle with the light: I am OK
• A light moving quickly left and right: a problem, I need help

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Memorize these signals and practice them with your buddy before every dive, because they may save a life.