Basic Scuba Diving Underwater Hand Signals

INDEX FINGER AND THUMB TOUCHING TO FORM A CIRCLE
This means okay and is used as a question and an answer.
PALM FLAT FACING DOWN, THEN TILTING IT SIDE TO SIDE
There's something wrong. Always point where after this hand signal so that people will know what's wrong.
'THUMBS UP' GESTURE
Ascend.
'THUMBS DOWN' GESTURE
Descend.

PALM FLAT FACING DOWNWARDS, THEN MOVING IT FROM LEFT TO RIGHT A COUPLE OF TIMES
Level off or stay at this depth. This is good for your safety stops.
FIST WITH THUMB OUT, MOVING IT IN AN 180 DEGREE ANGLE FROM SIDE TO SIDE A COUPLE OF TIMES
Which way? If you don't know which way to go, use this hand signal.
PALM FLAT FACING THE OTHER PERSON
Stop, stay where you are or don't do something.
TWO FISTS WITH INDEX FINGERS OUT, WITH PALMS FACING DOWN BRING THE INDEX FINGERS TOWARDS EACH OTHER AND AWAY FROM EACH OTHER A COUPLE OF TIMES
Where's your buddy or get close to your buddy.

ONE PALM FLAT FACING OUT TO THE OTHER PERSON, THEN TAP YOUR PALM WITH TWO FINGERS FROM YOUR OTHER HAND
Check your gauges. How much air do you have?
Remember these hand signals and you will not have a hard time communicating underwater.
Dive Safe!