What is the hand signal for "How Much Gas?"

The hand signal for "How Much Gas?" is indicated by an open palm with fingers curled towards the wrist several times. This signal effectively communicates the inquiry about the diver's air supply in a clear and intuitive way. The curling motion of the fingers towards the wrist suggests the action of wanting to know the remaining gas in the tank. This is especially important in diving to ensure safety and proper communication between divers.

While the other options may represent different concepts or signals entirely, they do not convey the specific question about gas supply. For example, an open palm with fingers held straight might be used for different inquiries or greetings, fingers pointed downward showing the number of tanks could imply the number of tanks available without specifically addressing gas levels, and a fist with a thumbs up typically represents a positive affirmation or 'okay' signal rather than a request for information about gas. Thus, the chosen hand signal, with its distinctive curling action, is the most accurate representation of the question "How Much Gas?" in diving communication.