Directionally Challenged...

[Rick Murchison]

Why not try the Underwater Navigation Specialty from your friendly SSI shop? It's a great basic course designed to teach you how to actually find your way underwater.
In Dallas, that's "Dive West" - they have several shops around town.
Rick

 

[scubadweeb]

Good news. I'm not in hospital or jail. I did however, accidentally discover a small family of skunks living underneath the hot tub in the back yard. No kidding! (No, I wasn't navigating under there - just passing by when I saw them). Needless to say, my local critter catcher was called and they were removed! Despite my adventure, the towel thing really does work! I'll keep practicing & as I'm heading to BWI in about 2 weeks, I'll let y'all know how the navigating under water goes. You don't think there will be any skunk fishes there, do you?

 

[The Chairman]

but I am sure you will raise a stink if you find any...

 

[scubadweeb]

(picture a face crinkling up) baaaad pun, baaaaaad pun! (love it)

 

[turnerjd]

Originally posted by Fishkiller
(soon very soon they're working on a underwater version)

Unfortunately not.

reasonably high frequency Radio waves don't transmit through water very well!!

this is the reason why submarines have to surface to communicate with the outside world, REALLY low frequency (in the order of seconds per complete wave, rather than waves per seconds) works, and is used to alert submarines to communications. (subs use a form of inertial navigation, pmus GPS fixes when the surface as far as I know)

GPS relies on high frequency radio transmissions, and as a result doesn't work underwater.

J

 

[Fishkiller]

I misspoke yes I know GPS will not work underwater unless you've got a long antenna. however the Idea of using a signal to locate yourself is being tested.

One system being tested by the NAVY effects the sonar of whales, BAD.
another are boat locators two peice units one at the boat the other on you, and will always tell you how far you are and which direction the boat is located.

however the basic principle of D=RT and the given density of water are being worked on..

 

[scubadweeb]

Isn't there a system used now that beams radio or Satellite "waves" from a transmitter on a first stage to the depth and air gages? (Or something along those lines)? Is that the start of an underwater navigation system maybe?

 

[Fishkiller]

Don't confuse the hoseless dive computers with navigation aids. A radio transmitter threaded directly into the first stage of your regulator sends tank pressure data to the receiver, which mounts on your wrist or BC.

For underwater navigation you should still be confortable with a compass, I just had to use an electric one to help me on land, and a underwater navigation course for when I SCUBA. I haven't heard or read of any magnetic compasses losing power yet.

 

[neil]

I understood that actual "radio" waves were difficult to transmit through water, and that the hoseless computers use something else. Or that radio waves were hard to transmit INTO water. Anybody know about this stuff, I'd like to know more.
Neil

 

[turnerjd]

Whilst I am not a physisist...

A good way of looking at it is think of light.... this is the same type of waves as radio waves, the deeper you go, the more you lose. - shows that transmission is not good - the light that gets furthest is the longest wavelength - blue - so - general rule is that the shorter the wavelength, the less the penetration. - GPS uses wavelengths shorter than light - therefore 'houston, we have a problem'.

For hoseless AI - there is only a short distance to bridge - so it is a bit like taking a torch (flashlight??) underwater as a light source - it works for a short distance - for the computer you just need a local transmitter powerfull enough that 1m away the signal can be read.

HTH

Jon T