How to use your whistle?

[Texas Aggie]

Single only, but don't make it too short. I've never timed it, but I'll bet I blow for at least half to 3/4 of a second -- maybe longer. At camps, all feedback on my whistle has been positive. I have been known to blow a few short tweets during a dead ball to keep a throw in from happening (e.g. sub or table issue), but this is something I want to get away from. The bottom line is that if for whatever reason you can't stop play with one blast, you need to blow a stronger blast, not 2 or more weak blasts. If you can be heard, what's the point of blowing more?

Never say never, as weird situations call for irregular action, but I'd say one strong blast on the whistle is almost always the way to go.