In an emergency situation on a river it may not be possible to hear people shout clearly as the sound of the water can drown out the quality of the sound. However a good whistle can punch through that.
The Fox whistle is probably one of the loudest and compact whistles on the market. I found out first hand how useful a loud whistle can be when I found myself trapped out of sight from the rest of the group. Despite shouting I wasn’t heard over the rush of the water. I carry a Fox Whistle on the shoulder strap of my PFD. I was able to use the whistle from this position without having to move my hands away from clutching the rock!
There are no moving parts and nothing that could actually fail, I don’t want a situation where something might break over time and has to be tested every time I go out for a paddle. It has to work first time, every time. The Fox 40 delivers optimum performance and sound power (115db) in a small, compact and super tough package. Given how good it is you’d probably expect the Fox 40 to be expensive, but they are not you can pick them up for around £5 or less.