Main Menu
Join Undercurrent on Facebook

The Private, Exclusive Guide for Serious Divers Since 1975 | |
For Divers since 1975
The Private, Exclusive Guide for Serious Divers Since 1975
"Best of the Web: scuba tips no other
source dares to publish" -- Forbes
February 2001 Vol. 27, No. 2   RSS Feed for Undercurrent Issues
What's this?

Blowing Your Horn

from the February, 2001 issue of Undercurrent   Subscribe Now

For divers on live-aboards in the deep blue sea, an air horn attached to the low pressure hose is often part of one’s safety equipment, supplementing a safety sausage. Supplementing, we say, because if you run out of air your air horn will not work.

Dive rmagazine tested four devices using a professional sound analysis machine to record sound levels. The human ear is most receptive to noises at a frequency of 2 kilohertz (2 kHz), so the volume was measured at that level. They also conducted subjective tests at a distance of 1,000 m.

The best device was the Buddy Blast, manufactured by AP valves. At 2 kHz its volume was 95.3 decibels (db) and could easily be heard at 1,000 m. “This was by far the loudest of everything tested.”

The Dive Alert, producing 83 db at 2 kHz could also be heard at 1,000 m. It was “a very loud unit ... but was not as good overall as the Buddy Blast.”

The Sub Alert (70.1 db Volume at 2kHz) “produced considerably less decibels than either the Dive Alert or the Buddy Blast. It made a very high-pitch squeal that could just be heard at 1,000 m.”

Trident’s Hammerhead (63.9 db Volume at 2kHz) “makes a very odd quacking’ noise, which was the least effective and could not be heard at 1,000 m.”

I want to get all the stories! Tell me how I can become an Undercurrent Online Member and get online access to all the articles of Undercurrent as well as thousands of first hand reports on dive operations world-wide

Find in  

| Home | Online Members Area | My Account | Login | Join |
| Travel Index | Dive Resort & Liveaboard Reviews | Featured Reports | Recent Issues | Back Issues |
| Dive Gear Index | Health/Safety Index | Environment & Misc. Index | Seasonal Planner | Blogs | Free Articles | Book Picks | News |
| Special Offers | RSS | FAQ | About Us | Contact Us | Links |

Copyright © 1996-2024 Undercurrent (
3020 Bridgeway, Ste 102, Sausalito, Ca 94965
All rights reserved.