Idea For Marking Great Dive Spots

[Jessica Anderson]

I was at a seminar at the Boynton Beach Dive Center this week about using the Navionics app for tracking your boating trips and marking spots. One of the guys in the audience had a really cool suggestion.
You can use the "Track" feature on the app to track you while boating. After you're done and you save the track you can scroll back through the route. The app tells you where you were at what time. The guy in the audience said that he was going to strap his phone in a waterproof case in a floating container to the dive flag and turn on tracking. When he saw something especially awesome he'd check his watch under water so he knew what time it was. He'd cross reference the time with the track when he was back on the surface and mark the spot.
I thought that was a really cool idea. Hey, if we can't have GPS under water this is the next best thing!

 

[CT-Rich]

that actually is a pretty cool idea. not sure I want to bring my i-phone into the ocean, even if it was in a water proof container ( on the other hand, it might be safer than in my locked but unattended car). I have had a few finds that I was never able to relocate on future dives. I think it would make planning future dives much more interesting. Just set a heading from a known location and off you go (or use a boat to get there).

 

[frogster84]

Why not use a waterproof gps tracker? Those are available for less than 100$ and there's less risk of theft and water damage.

 

[The Chairman]

The Garmin Virb XE will do that underwater and record video.

 

[JamesBon92007]

Hmmm... I have a "Where's My Car" app that might work for that. I actually DID take my phone (but it's only a Nokia) underwater in a $4 plastic bag case from China. Several times. The deepest was only about 30 feet but the only problem I had was being able to see the LCD screen and determine if it was recording or not( video).

 

[kelemvor]

Not sure if you can use old iPhones without service, but I know I've got a small pile of android phones that I've replaced over the years. Seems like a perfect way to reuse one, recording GPS data.

 

[tursiops]

The Garmin Virb XE will do that underwater and record video.

It is waterproof to 50m, but the GPS does not work underwater.
Actually, a lot of GPSs have a problem getting a satellite lock if they are right at the surface. So putting the GPS up off the surface, maybe on the top of the float, could work better.

 

[The Chairman]

but the GPS does not work underwater.

Doesn't need to. It has built in gyroscopes and motion sensors. Much like how a submarine does it. I have one, but I haven't used it yet.

 

[tursiops]

Doesn't need to. It has built in gyroscopes and motion sensors. Much like how a submarine does it. I have one, but I haven't used it yet.

I think you may be confused by the marketing info. The purpose of the gyro is to provide a stabilized video image, NOT to give an inertial navigation capability like a submarine. Likewise, the motion sensors are GPS-based, not acceleration and double-integration based like a submarine. There is nothing in the specs for the Garmin that says it will provide a track or a position underwater, only that it can do video and audio underwater. Trying to do what you think the Garmin does is the holy grail, and no one has done it yet in an affordable, consumer package.

 

[CT-Rich]

If you are buying a good quality sealed bag that can hold the phone and putting it in a zip-lock for a second layer inside the outer bag, you can attach it to the mast of your flag pretty safely. The odds of your losing it with the float is probably less than having stolen out of the car while you are diving.....

I would be interested in getting accurate data on some features while diving. and this would really be in the class of good enough for most creating reproducible navigational tasks.

I don't think you would be able to get GPS data of any great value from a phone with out a plan, because they use proximity to cell towers for a significant amount of their data. The idea will probably not work at all if the phone is out of range of cell towers on shore. I don't know if a sub $100 GPS like the garmin would record a path. The one I had only worked real-time.