The skip must follow the Laws of Bowls with regard to where he may stand in the rink. The official ruling on this is best explained by the World Bowls bowling rules themselves:
12 Position of players
12.1 In relation to the rink of play
12.1.1 Players at the mat-end of the rink who are not delivering a bowl must
stand at least 1 metre behind the mat.
12.1.2 Players at the head-end of the rink and who are not controlling play
184.108.40.206 behind the jack if they are members of the team which is in
possession of the rink;
220.127.116.11 behind the jack and away from the head if they are members
of the team which is not in possession of the rink;
18.104.22.168 on the surrounds of the green if the jack is in the ditch; or
22.214.171.124 well clear of the head if it is not possible to stand on the
12.1.3 As soon as a bowl is delivered, a player who is controlling play from a
position that is either level with or in front of the jack, must take their
position as described in law 12.1.2.
12.1.4 If a player does not meet the terms of this law, law 13 will apply.
When the skip controls the mat
It is interesting to watch the very top players when their team controls the mat. The skips get very involved in the head. Prior to the skip’s team rolling the next bowl, he might go right up to the jack, crouch down and explain exactly the shot that is required, using hand and body movements.
Once he has finished describing the shot that’s required he moves away from the head and moves to a position at least one metre behind the jack and wait for the bowl to travel down the rink. In the photo the skip is still crouching down, but he is positioned well behind the jack.
As soon as his team’s bowl comes to rest, the skip moves back to allow the opposing skip to control the head. Generally, the skip stands some distance behind the opponent skip when the opponent is controlling the head. But sometimes in social games the skips stand level with each other and chat…
Can you deliver a bowl when the opponent’s bowl is still moving?
No, you definitely may not do this. As long as the opponent’s bowl is in motion, the mat is controlled by the skip whose team member’s bowl is moving. Once the bowl has come to rest you may begin the process of waiting behind the mat for instructions from your skip and then delivering your bowl accordingly.
The Laws of Bowls are clear on this matter:
13.3 A player must not deliver a bowl before the previous bowl comes to rest and
possession of the rink has transferred to the opposing player or team.