Although many whistles can be used as safety whistles, we have Red & Yellow whistles specially made for us. These are upgraded versions of standard whistles (have non rust rings) and as we buy in 1000s they are cheaper.
There are two versions -
Users - based on the Slimline you find in life jackets etc, this whistle is designed for people participating in the sport. If you became injured or lost etc, then you need a whistle that easy to blow (you may have broken bones) and the sound carries well
Supervisor - whistle is a version of the Tornado 2000 which is the loudest whistle in the world. It is ideal for people supervising such as in baths, on the beach, for a group rambling or for general crowd control