I recently picked up a UST JetScream™ Whistle to see if all of the hype about how incredibly loud it is was actually true. I should note that I have some friends and fellow backpackers who scoff at me carrying a whistle with me when I hike and like to make lighthearted fun of it. I'll be the first to admit that it's probably the least sexy or technical piece of gear that I carry - but it is as important, if not more so, as any other piece of gear that I carry. So, to my way of thinking I should put as much effort into selecting and testing a whistle as I do anything else, which appeals to my inner gear geek!
The JetScream measures 2.3 inches (5.8 cm) in length and weighs 0.3 oz (8.5g) - not including the cord. It uses a compact "pea-less" design that works even when it's wet and which allows it to fit easily into a pocket or lay flat against your chest if worn around your neck on a cord or lanyard. The pea-less design also means it will not freeze up in cold weather or get jammed with debris.
According to the literature that came with the whistle, the JetScream focuses air through two harmonically tuned air chambers (seen on the sides in the photo above) to produce an ear-piercing 122Db shriek that is audible over most other natural and man made noises. In all of my outdoor testing the sound that was produced was nowhere near as loud as I had expected or hoped. The sound the whistle makes is indeed shrill and somewhat ear-piercing, but it sounds more like a high-pitched hiss than a perfectly tuned whistle tone. It is hard to describe. It is like the sound of air escaping under high pressure combined with a high pitched whistle, all at the same time. Maybe I have a slightly defective or misaligned example, but it is definitely not the "harmonically tuned" pure whistle sound that I was expecting. Note: I do not have any audio equipment for accurately testing decibel levels.
My usual whistle is the ACR WW-3 Survival Whistle that was developed for the US Navy and is USCG approved. Like the JetScream it is also a flat, pea-less design. It's made from high impact plastic which means that it is very durable and rugged enough for extended backcountry use. It continues to be one of the loudest emergency whistles I have ever used, and easily audible from great distances thanks to the crisp ear-piercing sound. Even at 102Db (again, according to the literature) it sounds significantly more loud than the UST JetScream.
Oh yeah, did I also mention that it is lightweight? The ACR weighs a mere 0.125 oz (3.5 g) - that's half the weight of the JetScream whistle and it measures 1 x 2 x .25 inches (2.5 x 5.0 x .6 cm).
I'm disappointed in the performance and sound of the UST JetScream whistle and will most likely continue to carry my ACR. I recently bought 5 more of the ACR whistles to make sure that I had enough for everyone in my family to carry one when we go on family hikes - it's loud, light weight and very affordable.
Disclosure: The author owns this product and paid for it using their own funds.
Brian is a Charlotte based backpacker, gear junkie, runner, and CrossFit(er). Originally from Southampton, England, Brian has lived in the US for over 20 years, finally settling in North Carolina. He spends as much time backpacking as his busy work schedule and family life will allow.