Over the years we have experimented with teaching various techniques to beginners in an attempt to introduce the system as successfully as possible. A Wing Chun teachers responsibility is to spread the art to as many people as possible.

Bong Sau translates as Wing Arm. This name is supposed to refer to the Crane (bird) using its wing to protect the breast from being attacked by the snake. This is why the bong sau is used to protect the body more than the head.

With a little movement the head can be brought out of danger, but the trunk will usually remain vulnerable, even turning would require some added safety to ensure protection.

Bong sau demonstrates many of the principles that build this system. Bong is used to protect an area effectively.

• The elbow is higher than the hand and offers good coverage.
• The bong sau will collapse safely under pressure whilst preventing the arm from getting trapped.
• Bong can transform to Taan Sau (Palm Up) and vice versa with ease.
• Bong Sau can be used at mid and upper levels.
• Beginners use bong frequently and often accidentally win a fight by using bong as a Jarn (elbow) strike.
• Bong Sau is used to help a student understand the centre-line.
• Bong Sau reinforces an understanding of the gates and body proportion.
• Bong Sau is the basis of Lok Sau, Dan Chi (single sticky hands), Sheung Chi Sau (double sticky hands), and the Mook Yan Jong (wooden dummy).
  

Some teachers have stated that Taan Sau is definitive of Wing Chun and whilst this may be true as an identifier, it is not as easily applied, as a defensive technique, as bong sau.

To learn to form a Bong Sau start by:

• Standing square.
• Place the knobbly bit on the little finger side of the wrist (styloid process of the ulna!!!) in the centre line.
• Ensure the elbow is higher than the hand
• The upper arm (humerus) is in a straight line pointing to the front.
• There is an angle slightly greater than 90 at the elbow
• If the above is adhered to your Bong Sau will be correct for your frame.

The blocking area for bong sau is the region of the ulna just above that knobbly bit again. The reason for blocking in this region is that it will be almost impossible to resist strong pressure, thus Bong will fold. This effect is used to our advantage in applying a very effective Laap Sau (deflecting hand) and Shat Geng Sau (chop to the throat).

Another reason for using this region is that it is close to the hand and co-ordination is far better near the hand rather than elbow. By not actually trying to block with the hand itself a greater area of your body is covered and the desire to hold unnecessarily is limited.

Bong Sau should be seen as a method of covering the body and locating the opponent's arm by establishing contact. It should not be seen as a 'block' whereby a clash is attempted. One of the major mistakes made in applying bong sau is when the practitioner lifts the bong to meet an incoming punch. The shape and direction of the movement are perfect for an opponent to set up a low punch counter.

Bong Chor Sau (wrong bong, applied to inside gate) is fundamentally more risky because the practitioners technique tends to fold onto themselves rather than diverting the opponents punch away.

Low Bong Sau is a completely different application. The technique is used to sweep across the body. It can not 'dive' down, as the danger to the fingers would be too great. The bong would also tend to straighten and make it less useful. The fundamental shape is very similar in that there is an angle in the slope of the forearm. However, if the angle were too steep the practitioner would dislocate their shoulder.

Bong Sau is usually applied off the rear leg in a forward stance and the weighted leg in a side stance. Bong Sau is taught from the front leg in the advanced class and adjustments are made to improve the power and balance. This is typical of most advanced training. A technique is taught and trained in a particular manner and when there is good understanding and 'feel' for the move, the rules can be bent. A student with experience is more flexible and adaptable in changing circumstances, and therefore responds better even if they make a mistake.