1st base coach leaving the coaches box

Question
How far out of the coaches' box can a first base coach go?  This involved a 14U girls' softball game, (in a tournament).  The situation was runners were on first and second for Team O.  They bunted, team D's 3rd baseman threw it wild into right field.  As the runners circled the bases, the 1st base coach ran down the first base line, to within 10-12 feet of home, basically yelling at his runners to run hard.  The coach was not telling the runners to slide.  After the play, the home plate umpire was asked by a coach on Team D about the coach's conduct.  The umpires were caught up in the action and did not notice, but they relayed the concern on to the 1st base coach, who argued he had every right to be where he was.

Answer
Hi Michael,

a coach may leave the coaches box to signal the runner to slide, advance or return to a base or move out of a fielder's way  as long as the coach does not intentionally interfere with the play.  ASA 4-7-c2a

He was IMO certainly signaling them to advance and had a right to do that.

mark