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scubasteve66
11-11-2007, 16:39
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:

kroorda
11-11-2007, 16:48
Your project sounds very interesting. Do you realize/understand the limitations of RF in water? One inch of water would attenuate a GPS signal to the point that it would be undetectable. Even the US Navy must raise a snorkel/antenna to the surface to receive a "GPS" signal. Nevertheless, if you have idea(s), I would certainly be interested and I would be happy to provide the info you request (above). Best Regards, Kent
PS: I have been diving for 35 year. I have dove many places around the world; favorite probably being the New Guinea area. I am in Colorado, and I have a pretty extensive background in RF.

Steve, I showed your thoughts to a friend of mine who is both a diver and an RF engineer. Here is what he said:

It's impossible to use GPS or other low-powered ultra-high-frequency RF device under water. Only VLF works there in the realm of 100-300KHz. These take impossibly long wire antennas to make work. They have to trail a long wire for it to work underwater on Subs and that will only give them 30-60 bits per minute for data speeds. This compared to the 1100mhz GPS signal that is transmitted from 250 miles up and passes large quantities of data (9600baud or 9600 bits per minute)

He's barking up the wrong tree and using flawed logic here even thinking that it will work. An underwater navigational device would have to work in the ultrasonic realm like our pingers.

gibson1525
11-11-2007, 18:06
this has some real potential. i would just like to put waypoints in so i could find a cave, wreck, trap, etc. with 100% accuracy. it would be nice to be able to jump in the water and be able to find something without having to worry about missing it. also, maybe think about setting up a website where people can upload the lat., long., and depth for things all over the world. i've been to several well known sites with some well known feature only to have the dive guide say "if i can find it, i'll show you this really neat thing." it would be very nice to be able to have it preprogrammed into you gps before you go so that you know exactly where to go to find what you are looking for.

maybe a feature to think about would be to have the unit automatically put in a waypoint where you descend, that way you could navigate back to your exit point. having a buddy tracker wouldn't be as important to me as i'm always in sight of my buddy.


a path for your dive would be a good feature, with depth also. depth, lat., and long. would be a must for all waypoints. if you are looking for a waypoint, i'd probably like to see where i am in relation to where the waypoint is (with depth, distance to waypoint, maybe even speed and estimated time until you reach the waypoint).

mitsuguy
11-11-2007, 19:45
when I read this, all I think is what comes with your basic standard Garmin like GPS - not the streets and maps type, but the type you can download topographical terrains to and set way points and history markers...

make that work underwater, and we're set... then do it for $200 (or less) and we are really set...

it would make diving new sites safer if you don't have someone already familiar with a site... it would also allow maps of past dives to be stored to allow new paths...

Navy OnStar
11-11-2007, 20:18
Current and limited visability are probably the two biggest problems with underwater nav. Anything that can fix your exact position (within a couple of yards) would be great. A good size memory to store many sites and a track history would work well for most everyone.

RoadRacer1978
11-11-2007, 21:20
I know this is still in the development stage, but what kinda market value are we looking at? Around the current GPS price $200-$500 or something much higher in the $1000's of dollars.

mitsuguy
11-11-2007, 21:45
I know this is still in the development stage, but what kinda market value are we looking at? Around the current GPS price $200-$500 or something much higher in the $1000's of dollars.

you can get an inexpensive, programmable, gps for like $75 now... most all of these inexpensive units even allow downloading of terrain maps, and waypointing up to 500 locations...

Clanggedin
11-11-2007, 22:16
The diving community would greatly benefit an underwater GPS device. It can't have a tether and should be able to carry a signal down to at least 100'. That would at least cover the majority of divers which are only OW certified.

As long as it has and can set a waypoint using depth also, then it would be awesome.

abcitydiver
11-12-2007, 00:42
without answering your questionaire in detail, yes, yes yes YES!
oh...an Atom 2.

If you build it, they will come. I promise. And though we'd all love this to be afordable technology, "affordable" is relative, and most of us would set up a lemonade stand for a year in death valley to afford this. imho.

scubasteve66
11-12-2007, 01:19
kroorda-

We are well aware of the GPS limitations underwater, which is why GPS doesn't exist there. Thank your friend for his input on pingers and ultrasonics; nature is a beautiful thing and often provides the most elegant solution to man's problems (dolphins and bats navigate/communicate the same way). The technical aspects aren't really the problem as we think we've come up with a cool 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.

Navy OnStar
11-12-2007, 01:45
What are your feelings about an underwater navigational device?
Would love one

What do you find most difficult about underwater navigation?
Limited Visability, Current, at times no reference point.

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

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?
Must have an easy way of picking what I want the computer to point at.

Have you ever used any devices (other than a compass) for underwater navigation, and if so, what were your experiences with them?
No, (Unless you count Dead Reckoning on a sub)

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?
Have not lost my buddy. But a system like the garmin rino would be nice to keep track of several people.

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

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?
Yes, Suunto Vytec DS. Has everything but the compass. Air integrated(would have got the one with the compass but too Much$$$$)

How often do you replace your computer, and what will you be looking for in your next one that your current model lacks? If there is one that has everything my previous one has plus navigation (more than just a compass I would consider it)

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): 5

Distance and direction to dive partner (or other divers): 3.5

Waypoints for dive features (caves, wrecks, etc…): 5

Actual map of dive site: 2

A recorded path of your dive (including air usage and swim speed): 5

Some facts about you:
Geographic location (state or country): Florida
Do you prefer boat dives or beach dives: Boat
Favorite dive spot:[/quote] Curacao

Navy OnStar
11-12-2007, 01:46
Same post more replies over in Accessories

abcitydiver
11-12-2007, 01:49
1)my feelings: drool.
2)everything, I'm a new diver, having done mostly drift dives, so I just seem to follow the pack.
3)Under 1 year. They havent.
4) logic dictates the answer, just like in my car, I WANT THE ARROW.
5) no
6)ive only breifly been separated, but can easily see it happening in the future, and any "out of sight" separation is going to be anxiety inducing.
7)safety, better dives, ie: faster location, less stress, better air comsumption, and yes... comfort
8) Atom 2. wrist. $680 with the ai transmitter.
Purchased it for being wrist mounted, air integrated, able to read buddies transmitter, ease of use, reliability, and simplification of diving tables.
a)distance & direction to boat: 4.8
b)distance & direction to dive partner: 10
c)waypoints: 4.97
d)map of dive site: 3.995
e) recorded path & data: 4
no california coast
i like both boat & beach
Let me explore for another decade and i'll tell you ;-)

det4220
11-12-2007, 08:42
The display would really have to be something new. The basic map images or the needle with distance and direction work well while on land, but in the water you have to add in depth. Waypoints could be at 160 ft., 100 ft., and 60 ft. on the same dive. The display would probably have to be some sort of hybrid with distance and direction (arrow) as well as depth (maybe something that looks like a depth sounder display, but with a small arrow as the "swimmer.")

A $200 Underwater GPS is unrealistic. Build it right and set the price appropriately. I know I would rather have a $2000 one that works right than a $200 that can't get a signal and floods.

CompuDude
11-12-2007, 14:23
If you can make it work, not only will you sell a ton of them to divers, you'll revolutionize things for the military and likely make a small fortune. Please let me know when I can buy stock in your company... once you have a working prototype, that is. ;-)

I would love one, but I'll tell you one area they fall short: They are very risky to depend on. If you fly by wire with your UW GPS(-like device) and have no good mental image of your location, you will be in BIG trouble if the electronic fail (leak, dead battery, random malfunction, etc.). Ask the forest ranger what their biggest hassle is these days, and they'll answer unqualified hikers who can't use a map and compass who call for rescue after getting lost because their GPS stopped working. The results could be considerably more tragic in the ocean.

CompuDude
11-12-2007, 14:34
And to fully answer the survey:

What are your feelings about an underwater navigational device?

Would love a reliable one!

What do you find most difficult about underwater navigation?

Visibility, keeping mentally aware of location even while distracted (camera, cool stuff to look at, etc.)

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

20 years, and I need help less, but it's always a challenge that needs to be kept forefront in your mind during an open water dive.

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?

Occasionally have problems, depending on the complexity of the navigation, distance needed to travel, buddy attentiveness, etc. I'd prefer to have both!

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

I have not, but I know a number of people who have been pretty happy with the systems sold by Welcome to Desert Star Systems LLC (http://www.desertstar.com)

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?

Only a few times, but it is always stressful until/if they are located. Longer than I'd like is anything other than spotting them immediately.

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

Safety, peace of mind, enhanced precision, reduced air consumption due to all of the above.

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?

Yes, $1200, Uwatec SmartTec, features (deco, wireless AI, large screen, everything on single screen, logging memory, IR data xfers so no proprietary cables, long life battery, warranty, etc).

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

~5 years. Bigger screen. Probably get a Galileo Sol next.

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): 5

Distance and direction to dive partner (or other divers): 5

Waypoints for dive features (caves, wrecks, etc…): 3

Actual map of dive site: 3

A recorded path of your dive (including air usage and swim speed): 3

Some facts about you:
Geographic location (state or country): California
Do you prefer boat dives or beach dives: No preference
Favorite dive spot: Catalina Island

plot
02-23-2008, 16:29
I suppose it'd be possible if you had 3 boats to receive signals from and triangulate a general position. The 3 boats would have to be sending signals acting like the gps sats, so of course it'd be limited to that small area... and that's if you could get a timing signal encoded in that's accurate. The technology to send data from the surface to divers is already there, think of the communications devices divers use to talk to the boat. Doing this though, you're probably looking at a $10,000 solution.

There's not way to boost the sat signals and relay them to the diver, as your precision would be out of wack.

Doing something like this though for shallow dives is to extravigant, and when you get to the level of diving done deeper, divers are probably beyond the need of a GPS unit.

I think before inventing the underwater GPS, a simplier yet still complex problem to look at would be to invent some type of homing beacon so a diver knows which way to go to get to the boat. You'll run into alot of the same problems though and probably need two signals X distance apart for it to work properly. Cost would have to be minimilized though for people to buy into it.

Just my ramblings on the problems you could potentially (and probably will) run into...

CompuDude
02-23-2008, 20:10
I suppose it'd be possible if you had 3 boats to receive signals from and triangulate a general position. The 3 boats would have to be sending signals acting like the gps sats, so of course it'd be limited to that small area... and that's if you could get a timing signal encoded in that's accurate. The technology to send data from the surface to divers is already there, think of the communications devices divers use to talk to the boat. Doing this though, you're probably looking at a $10,000 solution.

There's not way to boost the sat signals and relay them to the diver, as your precision would be out of wack.

Doing something like this though for shallow dives is to extravigant, and when you get to the level of diving done deeper, divers are probably beyond the need of a GPS unit.

I think before inventing the underwater GPS, a simplier yet still complex problem to look at would be to invent some type of homing beacon so a diver knows which way to go to get to the boat. You'll run into alot of the same problems though and probably need two signals X distance apart for it to work properly. Cost would have to be minimilized though for people to buy into it.

Just my ramblings on the problems you could potentially (and probably will) run into...

Everything you just described already exists. :)

The Navy uses ultrasonic transmitter buoys to allow their divers to triangulate their current position on hi-res underwater maps.

And a company called Desert Star (http://www.desertstar.com/newsite/sport/sportscout.html) already makes a homing beacon for the finding the boat. Just hang the little transmitter tube off the side of the boat, and a small hand-held receiver you dive with has a signal strength meter on it to get you headed back to the boat. Best, if you and your friends all get one, you only need one base unit and everyone can home in on the boat.

rye_a
02-23-2008, 21:40
For all your questions just take into consideration the difficulties that can come into play with map and compass overland navigation, then add in the difficulty created by currents, very low vis, no maps for reference, etc. I can say that from my perspective, underwater GPS would be VERY well received.

DarinMartell
02-24-2008, 16:57
To answer the question... Yes something like this would interest me.

I know the OP did not want to get into the actually methods of the device, but I can't help speculating on it. I could see this working if you had the specific area you where in mapped out and loaded. Taking a GPS reading at the surface before going under would "lock" the system to a point on the map and each movement could be recorded and shown on the map relative to the entry point in real time.

UCFKnightDiver
02-24-2008, 20:25
the army is already testing stuff exactly like what you just mentioned, the boat has a transiever your computer has one and then they put a float transiever in the water and it relays info to both dive boat and diver, the boat know where u are and what depth ur air supply as do your buddies know that same info.

Also the army is now using composite/carbon fiber tanks with a 5000 psi working pressure (tho not too many compressors in the public sector would fill to that :( sigh)

oh i was told this by an air force diver