Diving signal

Diving Signals are a form of sign system used by SCUBA divers to communicate when underwater.

Some diving equipment such as full face diving masks and diving helmets include voice communication equipment but most divers in recreational diving do not possess expensive equipment like that and must use Diving Signals.

Hand signals

[
cramping] In most situations simple hand signals are used. The most basic ones are:
* Thumb up = "let's go up"
* Thumb down = "let's go down"
* Circle with thumb and index finger, while keeping middle finger straight = "I'm OK" or "Are you OK?"
* "Cutting" or "chopping" throat with a flat hand = "I'm out of air".
* Wobbling a flat hand = "I have a minor problem"
* Waving the forearm in a wide arc = "emergency!"
* Hugging chest = "I am cold!"
* Hands indicating rising and falling chest = "I am out of breath!"
* Repeatedly clenching and unclenching fist = "I have cramp"
* Shrugging shoulders, arms bent, palms up = "I don't know" or "I don't understand"
* Index fingers of both hands extended, brought together repeatedly = "let's buddy up"

Signal variations

Diving signals sometimes differ between groups of divers. Some variations include:
* The throat cut signal: "general danger".
* Tapping the mouthpiece: "I'm out of air".
* Pointing at the ear: "I can't clear that ear"; or "listen!"
* Pointing at someone: changes the reference of the next signal from "I" to the diver pointed at.
* Pointing at side of head with screwing movement: "I am dizzy"; or "there is a boat moving about" (the screwing represents a propeller).
* First finger up/down: "lets go up/down".
* Thumb up: "I am OK" (often with naval divers); or "lets go up".
* Forming a large circle with both hands above the head: "I'm OK", as the OK sign can be difficult to see from a distance.

Divers sometimes invent local signals for local situations, often to point out local wildlife. For example:
* Both fists against sides of head: "I see a hammerhead shark".
* Fist with index and middle finger pointed out horizontally and alternately waggling up and down: "I see a lobster".
* Hand covering mouth, all fingers pointing outward from mouth and wiggling: "I see an octopus".

Other signals:
*hand flat thumb against forehead or chest: shark.
*moving hand across torse in wave motion: current.
*hands flat one on top of each other waving thumbs: turtle.

Torch / flashlight signals

The focused beam of a torch can be used for basic signalling as well.
* Drawing a circle on the ground in front of buddy = the OK signal
* Waving the torch = attention please!

Normally a diver does not shine a torch / flashlight in another diver's eyes but directs the beam to his or her own hand signal.

Rope signals

These are generally used in conditions of low visibility where a diver is connected to another person, either another diver or a tender on the surface, by a rope.

The British Sub Aqua Club rope signals are:
* One pull = OK? "or" Yes I am OK
* Two pulls = Stay put "or" I am stationary
* Three pulls = Go down "or" I am going down
* Four pulls = Come up "or" I am coming up
* Continuous pulls = Emergency: bringing you to the surface "or" Emergency: bring me to the surface

Public Safety Divers and many recreational divers use the following line signals while conducting circular and arc searches underwater.

Tender to diver
* One pull on the line: okay, okay?
* Two pulls: stop, take out slack, reverse direction
* Three pulls: come to the surface
* Four pulls: stop, don't move (there could be danger ahead or a boat entering the search area)

Diver to tender
* One pull on the line: okay, okay?
* Two pulls: advance line
* Three pulls: object found
* Four or more pulls: assistance needed