where to mount a whistle?

[Diveral]

I clip it to a d-ring on the left side of my BC under the inflator hose.

 

[Pathfinder]

Left hand pocket of the BC attached to a line so I don't lose it should I actually have to use it. The left hand pocket is reserved for the emergency type stuff, glowstick, sausage, whistle, small back-up flashlight etc.

Dave

 

[mamashark]

I have a parachute string about 4 feet long in my BC pocket which has my whistle and knife tied on it.

 

[lmorin]

I have one of these whistles

on the left chest D-ring. There is a hole across the right end of the whistle to which a lanyard is often attached. I drilled a 1/8" hole from top to bottom of the whistle (as positioned in the picture) such that the drill hole went right through (across, at right angles to) the pre-existing lanyard hole. I cut the clip (on the underside of the above image) part off the whistle because it seemed (and still does seem) useless. Then, the whistle was wire-tied to the D-ring with the mouth piece pointing down and away from the body. Thus, if I need the whistle, I rotate it upward and it is almost automatically at my lips in the correct orientation. The wire tie is snug enough so that the whistle does not float or flop around. This is a very loud whistle, by the way.

 

[cgamble]

I have my whistle on a lanyard that I just wear around my neck. The chest strap on my BC keeps it out of the way. You can tuck it in your wetsuit as well.