Now that my P3P is grounded after firmware update to 1.3.2 on Android (Disconnnected, no image), I have time to let you know what happened when my aircraft went swimming couple months ago.
Where I fly the only open spaces are bodies of water, lakes surrounded by huge forrests. I take off and land onto a floating dock (VPS off). Flying is always a pleasure, even with the known issues with Firmware 1.2.6 (VPS, tilted horizon, etc.) As I gained experience and boldness one day I decided to fly over a meandering creek. Altitude about 4 meters. All went well, until (Cursed fishers!) my Seven of Nine (handsome drone she is after all) hit a snagged fishing line strung across the creek. She fell into some 3 feet deep water. I was close, rushed in, pulled her out within 2 minutes or so. Motors were already stopped, and not by me, since in panic I forgot to pull the sticks down. I powered off the battery, removed it, and shook what water I could (vents came in handy). Props seemed fine.
At home I used a hairdryer, low setting, to blowdry all moisture - took about 15 minutes till I was satisfied she was dry. Then I noticed the camera protective glass had terrible condensation, I could see water inside. At the time I had no idea we could unscrew the glasss cap, so I opened up the case (torx 6), and the cmos plate (phillips). This permitted air circulation, and again I used the hairdryer, low setting, until condensation / moisture was gone.
Next came the battery. Tapping it against the palm of my hand I let the water out, and again used the hairdryer, as above.
All in all about 1 hr of fussing around I was satisfied that I did what I could, and went for a test flight. Everything worked as normal. I've had many happy hours since (Until firmware update to 1.3.2).
Hopefully this encourages someone not to give up when the aircraft goes diving (knock-on-wood).
Thanks for listening, and for all your hints in this forum - they've been very helpful.

Another happy ending... Glad it worked out for you. Others have experienced different findings after taking the plunge.
I hope you removed the nasty fishing line... ;-)

Enjoy flying another day...

RedHotPoker

Flying above water - the worse is when drone hit the bottom, then a divers are necessary.
I flied over water a few times but i think i mount a two plastic0.7L5 bottles to my Phantom in case of hitting water. It can be damaged, but it will be on the surface.Good you found your Phantom and it is OK.

Thats amazing that it still works and good to hear that is possible to resurrect.  

You lost me at "meandering" ... lol

Glad it worked out.  I live in Southern California and have been dying to fly over the ocean to film dolphins swimming and whales migrating.  But a salt water swim will not have a happy ending like your story.  It'd be toast.  

A drop into sea water might do some electronic damage to your aircraft, but it may still be salvaged. The technique is to carefully shake out as much of the water as you can, then immerse the aircraft in tub filled with distilled water. As you have to buy the distilled water, the best idea is to take the props off and put it in a large cooking pot to reduce the amount of distilled water required.. Leave it for several days moving it about in the water. After a couple of days, remove the aircraft and dry it and disassemble it as far as you dare, then dry everything with a hair dryer as RozBujnik suggested, just don't use a high heat. You may lose some components, but I have had to do this several times at work with electronic gear and often the damage is minimal.

Of course the real trick is to be able to recover the aircraft, and that is made much harder if it sinks, so I am looking to see if I can make my P3P float, as I do a lot of work around water too. It may be possible to fill spaces inside the body with shaped polystyrene foam, such as the arms. If not, then it may be possible to attach small flotation devices to the top of the aircraft, as long as you take care not to introduce much weight, or unbalance the aircraft or affect its streamlining.

A worthwhile project I think. I might makes some tests to determine how much foam is needed to support 1200 odd grams in water.

Geebax Posted at 2015-8-20 10:35
A drop into sea water might do some electronic damage to your aircraft, but it may still be salvaged ...

Archimedes tells you : to support 1320 g tou need to displace 1,32 cubic decimeter
so a plastic bottle 1,5L is OK, 2x 1L is better, 2x 1,5L platic bottles attached and The P3P is becoming hydro
quadcopter

I would buy a float(s) that inflates on contact with water. Otherwise, am concerned about wind drag on something as large as 1L plastic bottles. On the other hand if they save the bird I'll drink to that!

RozBujnik Posted at 2015-11-10 05:14
I would buy a float(s) that inflates on contact with water. Otherwise, am concerned about wind drag  ...

The mechanism to inflate floats on contact with the water would probably weigh more than the aircraft could lift.

No, not really. . . ;-)



RedHotPoker

Geebax Posted at 2015-8-19 23:35
A drop into sea water might do some electronic damage to your aircraft, but it may still be salvaged ...

Aloha Geebax,

     Bubble wrap, especially small diameter bubble wrap for small voids.  Bubble wrap comes in all kinds of sizes and shapes.  The plastic is tough, that is why it snaps so loud.

     Bubble Wrap - it is not just for pranking any more!

Aloha and Drone On!

Aloha,

     Plumbing and hardware stores also have closed foam hot water pipe insulation in various thicknesses and inside diameters.  Cut to a length that does not get in the way of the camera.  Fill any left-over voids with bubble wrap.  Zip-tie in place (trim the extra so it does not cut).  The space between the legs can also be filled with those big, clear, pillow-shaped shipping bubbles.  If you have not saved some, shipping and post offices usually sell them with the bubble wrap.

     Be sure to note the weight distribution of the P3 when you place your buoyancy.  The large heavy battery is toward the back, the gimbal and camera toward the front kind of like a see/saw.  But that is only if you want it to sit there so it can take off again.  Forget it if there are waves.  It is a salvage operation.

     "Look Ma - it is a drone on steroids!!!!"

Aloha and Drone On!