Question: What are hand signals used in beach volleyball
About the article "Beach volleyball", section "Block signals".

Candidate passages:
For the Summer Olympics there are 32 venues that have been or will be used for beach volleyball or volleyball. 
A temporary hand signal (臨時手信号, "rinji teshingō") is used when hand signals (other than substitute hand and passing signals) are necessary. 
The Occupy movement hand signals are a group of hand signals used by Occupy Wall Street protesters to negotiate a consensus.
The signals have been equated with other hand languages used by soldiers, cliques, or even Wall Street traders.
Hand signals are used instead of conventional audible signals, like applause, shouts, or booing, because they do not interrupt the speaker using the human microphone, a system where the front of the crowd repeats the speaker so that the content can be heard at the back of the crowd.
Between sharing of information on Facebook, Twitter, and other news reports, the hand signals have become common at other Occupy movement protest locations.
Some protesters go to neighboring groups to assist in teaching the hand signals along with other general cooperation.
There are YouTube videos showing the hand signals, though the signals are not universal at all locations. 
Hand signals are a form of sign system used by scuba divers to communicate when underwater.
The Recreational Scuba Training Council agencies have defined a set of hand signals intended for universal use, which are taught to diving students early in their entry level diving courses.
The more commonly used hand signals provide the following information:In most situations simple hand signals are used.
The RSTC signals include:   I am out of breath!
Hands indicate rising and falling chest.
Go that way: Fist with one hand, thumb extended and pointing in the direction indicated.
Go under, over or around: With palm down, hand motion used to indicate intended route to go under, over or around an obstacle.  
Rules and gameplay.
Rule differences between beach and indoor.
Beach volleyball is fundamentally similar to indoor volleyball: a team scores points by grounding the ball on the opponents' court, or when the opposing team commits a fault (error or illegal action); consecutive contacts must be made by different players.
The major differences between beach and indoor volleyball are: Playing surface – sand rather than hard court The dimensions of the court are 16 by 8 meters, compared to 18 by 9 meters in the indoor game.
The beach court has no "attack line", unlike the indoor court, which has such a line 3 meters from the net.
Team size – two rather than six, with no substitutions allowed Scoring system – best of 3 sets played to 21 (15 for a deciding set) rather than best of 5 to 25 Overhand touches and tips – open-hand dinks are illegal  A block at the net counts as one of the three allowed touches in the beach game, but not in the indoor game Open-hand setting standards are different in the beach game –double hitting is called tighter but lifts are slightly more lenient Coaching during matches is not allowed There are no rotation errors on the beach – players may switch sides at will It is legal to cross under the net in beach volleyball as long as it does not interfere with opponents' play Teams switch ends of the court every seven points, rather than between sets There is no Libero in beach like there is in indoor The only similarity in the courts used in the two forms of volleyball is the net.
In both versions, the height of the net is 2.43 meters for men and 2.24 meters for women.