Hand signals

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?" (Because divers sometimes wear mittens, this gesture can also be made without fingers extended - this variant can be used even by divers who are not wearing mittens at the time.)
• "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!"
• A diver giving the signal for cramping
• Repeatedly clenching and unclenching fist = "I have a cramp"
• Shrugging shoulders, arms bent, palms up = "I don't know" or "I don't understand" or "Question: ...?"
• 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: "let's go up/down".
• Thumb up: "I am OK" (often with naval divers); or "let's 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.
• Touching or tapping the top of the head with elbow extended sideways: "I'm OK" at a distance. Common in Monterey, California and Ontario, Canada.

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 torso 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. These date back to the time of the use of Standard diving dress.

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