RE: [PSUBS-MAILIST] sound transducers

["Andrew Goldstein" <ag@desertstar.com>]

All,

Even in fresh water acoustic conditions can vary quite a bit...esp. noise levels on a busy lake (Jet Ski's are LOUD)
SONAR gremlins are a particularly evil sub-species.

Jay makes an excellent point.  Having the performance quantified, so you know what your gear is capable of, may be even 
more important that having gear that at times may offer better performance.  I've certainly seen very expensive/high performance gear not work and the operator have no idea why.   Kinda like signal strength bars on a cell phone may be a better feature than more sophisticated voice processing or something.

Things like checking noise levels pre-dive or aborting dives on loss of comms help as well.

Best,
-a

ps.  David really neat work, keep it up.


-----Original message-----
From: "Jay K. Jeffries" bottomgun@mindspring.com
Date: Sat, 15 Nov 2008 14:48:23 -0700
To: personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] sound transducers

> David,
> 
> In open water (salt) you are going to have varying irreproducible results
> due to background noise (biologics + man-made), back scatter, reverberation,
> temperature, and salinity issues.  Most of these will degrade a given signal
> and reduce dependability.  Some days it might work and others it might not.
> Freshwater is a more reasonable environment for your endeavor.  It is a
> complicated process to determine the maximum range which will vary from
> place to place.
> 
>  
> 
> You need to be careful with casual underwater comms as you may be happy with
> relatively poor capability while chit-chatting but in an emergency, clear
> dependable communications is mandatory to increase the probability of a
> successful emergency resolution.
> 
> R/Jay
> 
>  
> 
> Jay K. Jeffries
> 
> Andros Is., Bahamas
> 
> 
> A skimmer afloat is but a submarine, so poorly built it will not plunge.
> 




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