GPS Tracking your dives

[BlueTrin]

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.

Thanks for explaining, could I attach it to my SMB ?

 

[MaxBottomtime]

My running watch overlays my track on Google Maps. When I pause at a red light I can see the cursor circling when download the watch. If you stopped at the anchor for more than a minute you would be able to see where it is on a map.

 

[tursiops]

Thanks for explaining, could I attach it to my SMB ?

Why would you want to do that? It will only tell you where the SMB is, it won't send that info anywhere.

 

[BlueTrin]

Why would you want to do that? It will only tell you where the SMB is, it won't send that info anywhere.

I was planning to drag the smb during the dive to get my location, isn’t it similar than to leave it on a float ?

 

[Chavodel8en]

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.

I guess if if was really important to you, you could swim in an X formation, with the X marking the spot. Or maybe in a circle would be easier.

 

[tursiops]

I was planning to drag the smb during the dive to get my location, isn’t it similar than to leave it on a float ?

Yes, that will work. Take care to put the GPS in a waterproof non-metal container, and try and mount it high on the SMB so it is not on the water surface.....it works better a bit away from the water. You'll need to keep tension on the SMB line so the SMB does not flop over into the water. It's tricky with an SMB, which is why a float is better.

 

[Lorenzoid]

I was planning to drag the smb during the dive to get my location, isn’t it similar than to leave it on a float ?

That's how I interpreted your question. Yes, a float is similar to an SMB, but I can't see how a phone or smartwatch could be attached to an SMB without the weight causing the SMB to flop over. A dive float is more rigid.

edit: tursiops beat me to it

 

[tursiops]

That's how I interpreted your question. Yes, a float is similar to an SMB, but I can't see how a phone or smartwatch could be attached to an SMB without the weight causing the SMB to flop over. A dive float is more rigid.

edit: tursiops beat me to it

I had to ask what he meant because one normally uses an SMB only at the end of a dive, and does not drag it around during a dive. The drag on a float is less than the drag on an SMB, so it is much easier to use a float to mark your location by GPS.

 

[emoreira]

This is an old idea and has been also promoted as a comercial device, but owing to low sales it was discontinued long ago.
https://www.researchgate.net/public..._computer_for_underwater_tracking_and_mapping
The main problem is that the diver has to carry the buoy where the GPS receiver is mounted.

 

[CT-Rich]

If you keep the float line fairly taunt, the GPS location should be fairly close. The more slack the less accurate. I already thought about how to mark a spot. A time stamp would probably work, but would require keeping notes on a slate and syncing your dive computer with your GPS. An easier solution is to swim out perpendicular to your heading to the found object 10 or 20 ft and back. You can see that I did that about where the cut-through between the rocks was. It depends on how sophisticated you want to get, I am using an old phone and the freeware version of the app. If I was serious about precise locations, I am sure a lot more could be done.