Underwater GPS

[SlurrySeal]

Ok, before you call me crazy I already know that the weak signal from GPS satellites cannot penatrate water. But what about this ....

http://www.delorme.com/bluelogger/

At first I was thinking this is a great little gadget that you could put in a waterproof container, then either tow around during your dive, or float to the surface to log tracking points that you could later to your computer to get exact locations of your dive. But then I stumbled across this...

http://www.geek.com/news/geeknews/2001dec/bpd20011207009191.htm

So bluetooth does work under water. The distance may be severly limited, but you would only need inches to sync the Blue Logger and your Palm/PocketPC underwater.

Ok, who's gonna try this first?

 

[Bob3]

Won't change a thing, your GPS antenna will still need to be at the surface.

 

[SlurrySeal]

Won't change a thing, your GPS antenna will still need to be at the surface.

Maybe I should describe my idea in more detail...

You attach a line to the Blue Logger, then float it to the surface, then retrieve it and when it is next to your palm/pocketpc the two sync using bluetooth and you now have your coordinates on and the pocket pc.

You also could just float it at the surface attached to you by a line and download the logged gps points after the dive.

In the SoCal forum a DFG Warden was requesting help in locating Illegal lobster traps with submerged floats. He asked if divers could report their location preferably with GPS numbers. If you have the Blue Logger with you (in a waterproof case of course), you could simply float it up on a line and walla - you have teh exact GPS coordinates of the illegal lobster trap.

The beauty of the Blue Logger is its small size 1.75" x 3.25" x 0.75" (like a thick business card). Even in a underwater case this thing would be small.

 

[archman]

In the SoCal forum a DFG Warden was requesting help in locating Illegal lobster traps with submerged floats. He asked if divers could report their location preferably with GPS numbers. If you have the Blue Logger with you (in a waterproof case of course), you could simply float it up on a line and walla - you have teh exact GPS coordinates of the illegal lobster trap.

Seems far simpler to just tag the site with a float line, and then run up with your boat and get a GPS fix. Wouldn't work for shore divers, though I hesitate to envision a shore diver lugging around a GPS buoy.

If you run a search on underwater GPS you'll find quite a bit of threads about this, many of which include similar DIY ideas. It seems this topic pops up several times a year. There ARE current underwater positioning systems on the market, incidentally. Rather pricey and complicated, however. The types that combine acoustical signals with GPS ones are pretty sweet.

 

[jonnythan]

Why on earth would you want to do this? How far do you actually swim in a given dive? Couple hundred feet, max?

 

[DeepTrip]

Why on earth would you want to do this? How far do you actually swim in a given dive? Couple hundred feet, max?

Well..... few hundreds feet is enough to get lost. I might consider one if they work.... not the bluetooth one, but something which you can bring in your pocket BC or in place of your compass.

I'll wait for the technology .

Benny

 

[critterc]

check this web site before you spend a lot of money


http://groups.msn.com/divergps

 

[captjohn505]

I did this one time with a gps to see how fast and what kind of track I was going in with a scooter.
I took my hand held gps in a water tight bag, mounted to two boat fenders
and about 30 foot of reel line.I had to use large ones so I would not pull them under with the scooter. And just pulled it with me on a scooter run in a lake we dive in.
you might be surprized at what you see on your gps when your finished with your dive.

 

[Pillow]

I did this one time with a gps to see how fast and what kind of track I was going in with a scooter.
I took my hand held gps in a water tight bag, mounted to two boat fenders
and about 30 foot of reel line.I had to use large ones so I would not pull them under with the scooter. And just pulled it with me on a scooter run in a lake we dive in.
you might be surprized at what you see on your gps when your finished with your dive.

How did it work for you?

We plan to put our garmin in a case straped to our float. We have to pull a float here anyway. Then we will use it with our scooters to run some of the coves in our lake.

If we find something of interest we will stop and swim right and left of our position thus making an X on our track.

We are cold water silty bottom and 2-15 ft vis so I think this should help us a lot.

What is your most efficient method for compass reading on your scooter? I have to stop to read mine because of the magnetic field from the Scooter?

 

[Tom Winters]

One of these days, someone will market a surface float/GPS antenna, a reel with line having a metal conductor cord core, and a GPS in an Otter box or underwater housing. The line drag will be something fierce if you're trying to go upcurrent with a scooter. But by God, you will know where you are.