The Fox 40 Sonik Blast CMG — the loudest whistle Fox 40 make, with a cushioned mouth grip. Finished in white / red.

Louder than the Classic by a useful margin, which is the entire reason to buy it. Distance is what a signal whistle is for, and every decibel buys ground.

Worth the extra over the Classic if the conditions you worry about are wind, surf, rapids or heavy forest — all of which eat sound fast.

Pealess means there is no cork ball inside. The old pea whistles jam when they freeze, choke when they get wet, and the pea eventually rots or sticks. A pealess whistle has no moving parts at all, so it sounds the same soaked, frozen or packed with sand.

Three blasts, repeated, is the recognised distress signal. One blast means I am here.

The cushioned grip means you can blow it hard, repeatedly, without hurting your mouth.