[pct-l] A whistle is great

[pct-l at mattmaxon.com]

Switchback mentioned a whistle as a useful thing...

I tend to agree, I started using a whistle as part of my canyoneering  
adventures and have made it part of my every day hiking gear.

Three short blasts universally signals trouble, a long loud blast  
waving arms will send most animals 2 or 4 legged packing....

If you fall or become incapacitated somehow a whistle can be heard  
over a long distance. It requires much less energy to blow a whistle  
than yell, it also cannot be mistaken for anything but what it is, man  
made.

I keep mine on my pack on a short tether. My canyoneering whistle is  
attached to my helmet.

Trail90