GPS Tracking your dives

[CT-Rich]

I have a few dives sites that are sprawling with plenty of interesting topography. The problem has always been is that visualizing where I went may not be very accurate. If you ever watch a novice diver trying to do a point to point transit, you can appreciate the problem. A few years ago I came across a large ship’s anchor standing uptight in the sand. I have a vague idea of where I thought it might be, but have never been able to relocate it under water.

Recently I tried something that will provide a way to track my dives using GPS. I took and old smart phone (my daughter was given a newer one when she finally got off my plan). It does not have service, but can still use WiFi and I down loaded an app called Strava. It is a GPS tracking software for runners and bikers and such. I attached it to the mast of my float inside a $5 dry box from Walmart. The results were pretty encouraging.

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• CT-Rich
• Jun 19, 2019

GPS tracking of dive

 

[edwants2dive]

What WIFI did you connect to? I wonder if the app would track without WIFI connection just using GPS. Awesome idea.

 

[Cirdan]

Strava, and many apps like it, can record the complete activity (including GPS positions) without an internet connection. After the activity is finished, and when there is an internet connection, the activity can be uploaded to the "cloud".

 

[BlueTrin]

That’s amazing, I was always told that GPS wouldn’t work underwater

 

[MaxBottomtime]

You can also do that with a runner's watch. I use a Garmin 35. It's water resistant, so I could attach it to a float, then upload the tracking to my computer.

 

[tursiops]

This is a solid and well-known technique. @BlueTrin please note the GPS receiver (old phone) is at the surface, not underwater. The diver has a line to the float and drags it around. There are small errors, of course, due to the diver not being directly under the float, but in relatively shallow water without strong currents, it works well.

 

[CT-Rich]

A smart phone needs WiFi so you can move the resulting data off the phone, not to collect the data. I usually wait until I am home or I make a hotspot with my regular cellphone after the dive. The gps won’t work if your float flips over. I had the phone already. There are plenty of GPS enabled gadgets that would work, it’s just a question of how much you want to spend and are willing to lose on a dive.

 

[Lorenzoid]

Clever, and looks like fun, but it doesn't solve the problem of how to mark specific waypoints, such as if you find that anchor again.

 

[tursiops]

Clever, and looks like fun, but it doesn't solve the problem of how to mark specific waypoints, such as if you find that anchor again.

Synchronize the time on your dive computer, and use the marking function if it has one. It won't be perfect, but close enough.

 

[-Moe]

Clever, and looks like fun, but it doesn't solve the problem of how to mark specific waypoints, such as if you find that anchor again.

Perhaps an app that logs time stamps with the lat/long datum can be matched to an observed time underwater.

Edit: just noticed that the reply above already covered this point.