Question on GPS

[Matsya]

I got into a discussion witha friend of mine about underwater navigation and he asked me if there were any GPS systems for diving. I didn't know the answer and I thought the best place to find one was this forum. So can anyone tell me about GPS Navigation for scuba diving - whether any systems are available and how good they are?

 

[herman]

There are none, GPS signals will not penetrate more than a few inches of water. You could float an antenna on the surface and have the GPS below but I am unaware of anyone selling one. More trouble than it's worth to me.

 

[97fxdwg]

I am only guessing here but I'm a Land Surveyor and use GPS systems daily. Since the information is being broadcast from satellites and is very much a function of time, "How long did it take the signal to get to the receiver = distance from satellite", I wouldn't expect those same signals to make it through the completely different medium of water, at least not and still be usefull regarding the time issue.

my 2 cents

 

[Codyjp]

correct, not a chance underwater. what i would like though is a really really good waterproof bag for my GPS so i could use it to find a wreck offshore, then store it and go under. anybody have sugestions?

 

[Wildcard]

Pelican case.
"Waterproof" GPS and VHF units sold for marine use are not. They may be somewhat splash resistant but far from waterproof. Found that out one day as I was broke down and drifting offshore headed for Guam, 1000 miles away.
There is a GPS unit for UW use I saw somewhere but it was spendy. Had a reel for a floatable antenna. Mlitary use kind of thing.

 

[Guba]

I've seen preliminary devices for the military. The system does, indeed, use a buoy based GPS, with several acoustic "pingers" attached to either individual divers or stationary relay stations on the floor. (They can also be suspended on a down line from the GPS buoy. A computer interface relates the GPS coordinates to the acoustic pingers and provides data to any associated readout systems.
The idea is to let divers navigate in totally "blind" enviromnets. By the way, there is also an interface for a "heads up" mask in which all nav data as well as diving computer functions are displayed INSIDE the mask. Talk about high tech! The military boys get all the neat toys. Now, if we can only work out those bugs in the system...

 

[CuriousRambler]

There's a discussion somewhere on SB that's just a few days old about this. I think it's in the equipment forum. People are starting to float a GPS in a pelican case on the surface, attached to a line and towing a dive flag, if you need to check your position you tow it down to your depth and read/mark it. Not the best operational idea, but probably the cheapest and easiest.

 

[Notso_Ken]

correct, not a chance underwater. what i would like though is a really really good waterproof bag for my GPS so i could use it to find a wreck offshore, then store it and go under. anybody have sugestions?

I haven't worried about a waterproof case for mine, I just take it out just prior to getting to the dive site, let it lock on, save the position, turn it off, and stash it back in by dive bag. Haven't had a problem on 3 boat trips.


Ken

 

[my1ocean]

Think the previous threads pretty much sum up the no under H2O GPS question. There used to be an underwater acoustic navigation system for divers to hook to an achor line with a wrist worn reciever. They're hard to find now as they gererally don't do a good job.

We're stuck with compasses for now.

 

[Codyjp]

I haven't worried about a waterproof case for mine, I just take it out just prior to getting to the dive site, let it lock on, save the position, turn it off, and stash it back in by dive bag. Haven't had a problem on 3 boat trips.


Ken

Well, scratch the waterproof bag idea, i will just buy a boat. A simple solution really.