Underwater GPS

[ArcticDiver]

Even if you have never used or heard of the Scuba-Nav before I'd be interested in hearing your opinion of it.

Basically, this is how it works.

The Scuba-Nav has a remote GPS antenna which is mounted to a dive flag float. The antenna has a 55 ft cable which is an attached to a GPS unit in a waterproof housing. The GPS satellite signals are sent through the antenna to the GPS reciever that the diver carries underwater. This allows the diver to know where he is underwater.

I haven't done a lot of shore diving but want to do more and thought this would be a great way to get back to where I started from! Or to navigate out to someplace I wanted to go, like a wreck or something. Many have already been given GPS coordinates that you can program into your GPS and then use it to get there with.

Anyway, I'm interested in what others think of this.

A 55 ft cable? The GPS unit will tell you where the Antenna is not where You are. Depending on how deep you are diving You could be anywhere from directly under the antenna to 55' away. Is a location with that big a diameter accurate enough for what you do?

If so why not just get one of the waterproof Garmin units and mount it to the float?

 

[got4boyz]

A 55 ft cable? The GPS unit will tell you where the Antenna is not where You are. Depending on how deep you are diving You could be anywhere from directly under the antenna to 55' away. Is a location with that big a diameter accurate enough for what you do?

The cable is used like your line on a dive float. If you are only 30 feet deep you wrap it around a reel so only 30 feet of the cable is out (I believe the cable is marked every 10 feet), so essentially it would be almost above you. Of course it would be slightly behind you since you are pulling the float with the cable, but that only means you reach where you are headed a few feet before the GPS unit shows you are there.

 

[coliseum]

Its a good idea but it would be a bit of an annoyance having it connected to you the whole time!

 

[Don Burke]

It looks to be one step short of being done right.

55 feet of antenna cable (abused cable at that) is going to be pretty lossy at 1200 MHz.

I'd put the GPS receiver in the buoy and run the data down a fiber optic link to the diver.

Have you thought about one of those SONAR systems that tells you how to get back to a transmitter set? No wires is always a good thing.

 

[got4boyz]

Its a good idea but it would be a bit of an annoyance having it connected to you the whole time!

Many people dive with dive flags attached to them all the time don't they?

Have you thought about one of those SONAR systems that tells you how to get back to a transmitter set? No wires is always a good thing.

Never heard of a SONAR system. How does that work?

 

[Gary D.]

It looks to be one step short of being done right.

55 feet of antenna cable (abused cable at that) is going to be pretty lossy at 1200 MHz.

I'd put the GPS receiver in the buoy and run the data down a fiber optic link to the diver.

Have you thought about one of those SONAR systems that tells you how to get back to a transmitter set? No wires is always a good thing.

Those little units are perty cool. I've been able to play with them a couple of times.

One just has to remember to still keep up the navigation skills and not rely on the little electronic tubes. You never know when one of the two little units is going to display the middle finger and take a siesta.

There is a real nice wireless GPS unit out there. Just a big pain to use for sport diving. Besides it works on a frequency that appears to attract sharks for a less than frendly encounter. They like to bite the unit the diver carries.

Gary D.

 

[DoUDive2]

I'm a big GPS fan, but dragging a bouy around behind me all day long is not something that I do for fun. This system is not any good for deep diving since the bouy umbilical is only 55' long. Also remember that if the wind changes the location of the boat can change during the dive. Trying to preload the the location of the anchor point on the seafloor is a non-trivial mathematical exercise. Any diver that can use this this device to reliably find the boat anchor is probably already very good at underwater navigation.

Other than that, it sounds like a great gadget!

Chris

http://www.longbeachdive.com/scubanav-detail.htm

Has anyone heard of or used this Scuba-Nav? I came across the website doing a search for dive flag floats. Sounds interesting and I'd like to try it, but kind of pricey without knowing how well it really works and how easy/difficult it is to use.

Any thoughts would be appreciated.

Thanks

 

[archman]

at this recent locale.
http://www.scubaboard.com/t27622.html

The last postings were a week or so ago. Unfortunately it's hard to run a search for "GPS" as it's only three letters long (and thus excluded from search criteria). I'm sure tech admin will eventually get enough complaints to rectify this.

 

[DivemasterSteve]

at this recent locale.
http://www.scubaboard.com/t27622.html

Unfortunately it's hard to run a search for "GPS" as it's only three letters long (and thus excluded from search criteria). I'm sure tech admin will eventually get enough complaints to rectify this.

all you need to do is put * in it when you search and it will give you what your looking for. *GPS will work fine.

steve

 

[Don Burke]

Many people dive with dive flags attached to them all the time don't they??

I'm not one of them. The float would have to be big enough to keep the antenna clear of the water and small enough to not be a big source of drag. That's a tough balance to strike.

Never heard of a SONAR system. How does that work?

Here's a discussion about the SONAR gadgets.
http://www.scubaboard.com/t26321.html

Many rave about them. I've never tried one.