Hello,

we have a Phantom 3 Professional and we use the drone for surveying (photogrammetry). For our work we fly 90% of the time above or near rivers and lakes.
The last 2,5 years nothing happend, but three weeks ago the drone crashed into the Danube. It was only 2-3 meters away form the bank and about 0.5-1 meter deep. The water was so cloudy, that five people couldn't find the drone.

We bought a used Phantom 3 Professional and now we think about, how can we get the drone back, if this happens again?
Have anyone a idea, how to get a drone out of a 1 to 50 meter deep water?
Or is there something similar to a automatic lifejackets, which can lift the drone?

The only think I found is this:
GetterBack
Are there any outher thinks k

The GetterBack is a commonly used option and one that's easy to attach to the Phantom landing gear. The only issue is that it will only allow you to recover your Phantom in up to 100 feet of water.

https://www.amazon.com/exec/obidos/ASIN/B01891TFXO

Hi Seraph, we're sorry to read the accident. For the watered drone, it is not recommended to repair as some internal parts might be oxidized and stability cannot be ensured. If the unit is under warranty period and DJI GO was connected at that time, you may contact our support to start a case to analyze. Hope for your understanding.  

@DJI Susan
We don't want to repair the drone, if it was waterd. I know the fact about oxidation...
The only reason for my question is, that I want the photos from the SD card, when it was under water.
As I mentioned we didn't find the drone, because we couldn't see through the water. So we are search for something, which pulls the drone to the surface or indicates the position of the drone under water.

It was only 2-3 meters away form the bank and about 0.5-1 meter deep.

Did you try using a grapple rake on a rope?  

If water is flowing, drone could be down stream from where it went in at.

We didn't have a rake with us. Only some plumb rods.
Five of us went into the water and we searched in lines.
We searched a area of ~20 meter from bank and about 80 meters downstream and ~20 meters upstream.
The river current was relativ low in the crash area, but there was so many big stones inside. We searched about 60 Minutes. Some big ships passed and then we stoped seariching, because there was low tide and every ship sucked the water and the surface of the water dropped 0.25-0.5 meter...
It was one of the nearby limbs:

We flight with the pix4d app and the signal of the camera fall out for 1-2 seconds and the pilot did't watch direct to the drone...