I used the Fox 40 Classic for many years as a lifeguard.  You do need to be very "deliberate" when blowing the whistle, but once you get used to it, this shouldn't be an issue.  If it's any indication of how loud this whistle is, I actually made my own ears ring many times because I blew too hard.  I could also hear a coworker's whistle from almost a mile away over all the ambient noise.  When I changed jobs and the lifeguards were given metal pea-type whistles to use (those are a joke, by the way), I continued to use a very old, very chewed up Fox 40.  There's never a "pea" getting stuck in the chamber, and no part of the whistle itself can rust like a metal whistle.  Also - because of the plastic construction, you can run this thing through the dishwasher without a problem.  And, if I'm not mistaken, the Fox 40 will float if dropped in water.  The only real 'con' is that you can actually chew the end right off if you use it enough.  Even though my waterfront days are (mostly) behind me, I'm restocking my stash of Fox 40s for emergency use!