Underwater Navigation Device

[scubasteve66]

I’m working at USC as a researcher in the Aerospace and Mechanical Engineering department, where my group has come across some interesting technology. As a project for a class, we are looking into the feasibility of bringing a device to market that would function as an underwater GPS-type navigation device. While we’re working on the best way to do physically do this, we’re also looking into whether or not it is even worth trying. If you would be interested in such a device, or think it’s idiotic, input from anyone is greatly appreciated. If you have a few minutes, please fill out the brief survey below. If you’re time limited, answer whichever questions you’d like. Thanks in advance!

What are your feelings about an underwater navigational device?

What do you find most difficult about underwater navigation?

How long have you been diving, and how has your answer to the last question changed as you’ve become more experienced?

When looking for a specific feature at a dive site (cave, wreck, etc…) how often do you have difficulty find it? If you’ve had difficulties with this, would your rather have a map to look at, or a simple arrow telling you the distance, direction, and depth to the feature?

Have you ever used any devices (other than a compass) for underwater navigation, and if so, what were your experiences with them?

How often have you been separated from your dive partner? Of those times, how many times have you easily found them, and how many took longer than you would have liked?

What would be your biggest reason for purchasing a navigation device (safety, better dives, comfort, etc…)?

Do you use a dive computer? If so, what type do you use, how much did it cost, and what made you purchase your particular model?

How often do you replace your computer, and what will you be looking for in your next one that your current model lacks?

If your next purchase of computer had an option for a practical navigational aid, how strongly would you consider the following features? Please rate from 1= Unnecessary to 5=Important, and add any comments you feel are necessary.

Distance and direction to boat (or dive starting location):

Distance and direction to dive partner (or other divers):

Waypoints for dive features (caves, wrecks, etc…):

Actual map of dive site:

A recorded path of your dive (including air usage and swim speed):

Some facts about you:
Geographic location (state or country):
Do you prefer boat dives or beach dives:
Favorite dive spot:

 

[Bob3]

Ummm... The radio frequency that the GPS signals are on has very poor penetration into water.
Folks have been looking into the U/W aspects for quite a while.
You're going to need to get into the ULF band for any sort of radio signal depth penetration, making a surface repeater necessary, or at least an antenna that's extending to the surface.
Gyro stabilized devices seem to be the better answer, along the lines of an old-style autopilot.
(that's what the torpedo guidance systems use).

 

[cinder4320]

I am a recently certified Intro Cave Diver in Florida. As a wetland/wildlife biologist I use GPS and GIS technology on land quite a bit. I would love to have some sort of underwater GPS device that would allow me to take points with notes and then once on land display them over aerial photographs (i.e. ArcView, GIS compatible).

As a cave diver it would be "neat" to see where exactly I was underground laid out in GIS. I would not really interested in using a GPS for navigation but rather for point taking and future map making once back on land. (Just in case you are curious this Trimble - GeoXH Handheld is the land receiver we use).

Miranda

 

[scubasteve66]

Bob3-

We are well aware of the GPS limitations underwater, which is why GPS doesn't exist there. The technical aspects aren't really the problem as we think we've come up with a novel way to deal with them. The real problem for us is what does a diver REALLY need? What I mean by that is simple: if you bound the problem with a solution and say "I need GPS" you're thinking about the possible solution without analyzing the problem. We're more interested in what is the actual problem that needs to be solved, which is why the questionaire doesn't have any technical questions. How a diver finds cool things under the water has nothing to do with what technology ends up being used, and we're trying to find out what's most important to the community as a whole.

 

[scubasteve66]

Miranda-
Thanks for the response. Getting to caves may be possible at this point, but navigating around inside them could be hard (at least with our design). It's a hugely difficult problem, because line of sight is non-existent, and reflections from the walls make reliable signal very very difficult to attain. Something we are thinking about though, and the link to GIS is an awesome idea. Something we're worried about with that is topos... in your experience, how consistent are underwater features? It seems like caves and wrecks don't move drastically, but that general current/tidal motion would render detailed topos useless relatively quickly.

 

[vixtor]

Having a navigation device (like GPS) would be great. It can be either a simple arrow pointing to the right direction and eventually displaying distance (but distance is not really needed, you can be aware of distance when above water, and then swim until the arrow turns) or a basic blanc map with waypoints on it, whatever is easier.

By the way, an important feature would be the ability to mark waypoints - this is equally important to the feature of navigating towards them. If the waypoints could be mapped (on the device or later on the computer) in order to integrate them in normal maps, that would be perfect.

A very important feature would be precision. On land, an error of 10-20 meters is not that bad, but in water an error of 3 meters can be the difference between seeing and not seeing the target.

 

[miketsp]

See the first few posts in this thread (post #5 on):
http://www.scubaboard.com/forums/do-yourself-diy/63064-diy-dive-computer.html

 

[extremedivers]

gps underwater only exists with huge make up antennas at the surface in several sets as used in the
phantom elite commandos divers.for a small underwater gps it will be quite a hard work cause lots of
electronics is needed and lot of space will be needed so it wiull be at the end like the size of a car, but nothing is impossible and every problem has a solution has a solution so I will encourage whoever wants to work on it.Thanks Pte 20681 Commandos diver

 

[kayakdiver]

*I've been using gps underwater for about 10 years (no data cable / external antenna)...you can find my video on Youtube...just search "underwater gps"---a link for a free book is listed at the end. The original method (as seen in Underwater Magazine and Divespots.com), was a deploy and recover method (Magellan)...the newest adaptation will be made obvious by the video.
Mark Thome, FL Keys divergps@hotmail.com

 

[danvolker]

I could imagine a small to medium sized chartplotter made waterproof to 200feet, connected to an ultra-thin wire ( fiber optic, or some high tech wire with required conductivity as well as tensile strength and ability to be rolled up in a reel) --and this connects to a dive-flag-float with a GPS antennae in it....the float should be an inflatable torpedo float ( like Riffe makes) so that the line can be kept very taught--i.e., go nearly straigh up, with virtually no drag to the diver pulling it.

On a complex reef system, the diver could see where on the crown they are--where they want to be ( inshore ledge or offshore ledge near some special structure--say like a horseshoe shape in the reef, or a large cave, or some structural feature the diver wants to find. The unit would have the 3d look of Garmin chartploters, and obviously the diver could mark gps locations of any cool new structures they find---great for future boat drops.

Sell the unit for twice what a Galleleo dive computer costs..say for $2500 to $3500 and it would sell.
Dan V