The boundary umpire is the sole judge of when the ball is out of bounds, except when the field umpire awards a mark before the ball passes completely outside the boundary line or awards a free kick, or a goal umpire over-rules the boundary umpire in relation to a score or when the ball hits or goes directly over the behind post (in which case the goal umpire directs the boundary umpire that the ball is out of bounds).
The goal umpire may over-rule the boundary umpire if he considers that the ball has passed across the goal or behind lines and the boundary umpire signals the ball out of bounds, or the goal umpire considers that the ball has not passed across the goal or behind lines and the boundary umpire is of the opinion that it has.
If the ball goes outside the boundary line near the behind post and the goal umpire is in a better position to see than the boundary umpires and/or the boundary umpire is looking to the goal umpire for assistance, the goal umpire is required to assist the boundary umpire by indicating as follows:
Whilst these indications are to assist the boundary umpire, the decision is still the boundary umpire's responsibility. However, when caught behind play or out of position, they should look to the goal umpire for assistance.
In instances where the boundary umpire has been positioned at the behind post, they must wait until the goal umpire has given their decision before moving away from the behind post.
When the boundary umpire is positioned at the behind post and the ball hits the behind post on the full, the boundary umpire will tap the post three times after signalling out of bounds.
Where the goal umpire is giving assistance regarding normal out of bounds signal (no hitting of the behind post) they are not to continue giving signal until acknowledged. If the boundary umpire does not see the signal, or chooses to ignore it, the goal umpire is to resume normal position and if necessary indicate and record any subsequent score.
When the ball passes across the goal or behind line resulting in a behind, and the boundary umpires are not by the behind posts, the goal umpire will clearly tap their chest three times. This will indicate to the boundary umpires that if the goal umpire receives an "all clear" from the field umpire, they will be signalling a behind, therefore informing the boundary umpires that they do not have to run to the goal area to pick up the ball.
Where a mark is taken on or just before the goal line, the goal umpire shall immediately place his hands behind his back and quickly back away, keeping his eyes on the ball at all times.
Where a mark is taken just behind the goal line, the goal umpire shall step up to the line and look to the field umpire for an all clear. If all clear is not immediately given, the goal umpire is to run out to the field umpire and seek all clear, provided a free kick has not been awarded to a defender prior to or at the same time as the score.
If the field umpire awards a free kick or a 50 metre penalty to a forward concurrent with their being a score (e.g. a player is downed after kicking but the ball goes through for a score), then:
If there is any doubt in the field umpire's mind about whether a goal or behind has been scored, he will immediately run to the goal umpire to clarify the situation. In this case, the goal umpire should run to meet the field umpire as soon as he/she realises that the field umpire wishes to confer with them.
When the field umpire is 100% sure the ball has hit the goal post, he will give all clear whilst tapping one forearm with his other hand three times. If the field umpire gives this signal and it appears obviously incorrect (out of context) the goal umpire is to run out and talk to the field umpire before making a decision.
When the field umpire sees the ball go out of bounds close to the behind post and the boundary umpire is caught out of position, in order to assist the field umpire will signal to the goal umpire by extending his arm with clenched fist at a 45 degree angle to his body. The goal umpire then makes the appropriate signal to the boundary umpire who will signal out of bounds.
Any umpire can commence the consultation process. However, the field umpire will control the process. This process is commenced if for any reason there is uncertainty about a decision or course of action that may be required and may involve a boundary or goal umpire.
From a goal umpiring perspective it will in most instances be in relation to the value of a scoring decision or if in fact there is a scoring decision. Regardless of the purpose of the consultation an umpire should not get involved if they cannot add value to the process.
If for example there is a scramble for the ball on the line and the ball crosses the line with the goal umpire uncited then a consultation will be initiated to determine the result and the boundary umpire might have been in a better position then they would assist in the consultation process. If in this situation a decision cannot be reached then the lesser result would be awarded, in this case it would result in a behind.
These tips have been provided by Nick Abbate (QAFL - Goal Umpires Coach). Local rules and regulations should take precedence over any specific advice provided.