The Storm Whistle in black — a pealess safety whistle designed for the conditions that defeat ordinary whistles.

It is built around one problem: being heard when the environment is working against you. Wind, surf, rain and running water swallow sound, and a whistle that is loud in a quiet room can be useless beside a creek.

It also sounds underwater, which is why these turn up in marine, swiftwater and rescue kits rather than only on lanyards.

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

If your trips involve rivers, the coast, or weather that actually arrives, this is the step up from a standard whistle.