We all know that if you have a drone, sooner or later you're going to have a crash; however good a pilot you are. Undoubtedly one of the worst places to see your prized machine fall out of the sky is over water. Drones are either treasured toys or valuable pieces of business kit and if they do end up in the drink you are potentially in a lot of trouble.
You could be in it up to your neck or even deeper if you don't take this first piece of advice: don't take a running jump or start paddling into the water to rescue your soggy bundle of electronics, however much it cost you. You could be putting your life at risk. Spend a few seconds working out the safest way of recovering your drone or even whether it's too dangerous to attempt to retrieve it. We hope the guy in the video knew how deep the water was.
Crashed your drone into water? What to do first
As soon as your UAV gets wet it's likely that one of the ESCs (electronic speed controllers which regulate the power going to the motors) will blow like a fuse. Each motors has an ESC connected to them or even integrated into them and, if one of them has blown, it'll save you having to do the first important job, which is to turn the power off and remove the battery. Of course some drones don't have switches so you'll need to disconnect the battery and check that it hasn't been damaged. If it has, put it somewhere safe because lithium polymer batteries can burst into flames even if they have been dunked. The best advice is to get rid of the battery altogether at a proper disposal facility. You won't be able to rely on it again.
This next comment isn't meant to sound flippant but, if you have the choice, avoid crashing in salt water. It's full of all sorts of nasty chemicals that will cause corrosion or electrical shorts. If you're unlucky or even downright careless don't try to dry your aircraft straight away. Do something that is counter-intuitive and rinse it with fresh water. Better still use distilled (de-ionized) water because it won't have salts dissolved in it. Tap water will be second best because there are chemicals in that too but it will be better than sea water.
Dry off any visible water with a cloth and check for any water still visible on the motors. Modern drone motors aren't normally affected too badly by water because they are brushless and, as the name suggests, they don't have brushes or a commutator. At the same time as you're doing this tip out as much water as you can from inside the plastic shell, that's if your aircraft has one.
Check your warranty
If your drone is still covered by the warranty, there's little more that you can do except put it in a dry, warm and ventilated place until you can send it off to your supplier. If you start unscrewing your Phantom you will invalidate the warranty even if you have got a set of the correct, specialist screwdrivers. If you suspect that the crash happened because of a fault, the supplier or the original manufacturer will be able to look at your drone's flight logs to see if it was a product failure or a mistake by the pilot. If your drone was faulty you should be entitled to a replacement.
There are plenty of electronics that can be affected by water inside a DJI Phantom
The heart of smaller, hobby drones is usually contained in a single printed circuit board. The main board costs around £350 without any labour charges but if the 4K camera needs replacing it will set you back £450 plus fitting. With figures like that you might have to consider replacing rather than repairing. A new drone could easily be cheaper than a rebuilt one.
The camera gimbal may appear to work perfectly normally when you've dried it out but the same can't be said for the camera. The lens and the sensor will almost certainly be seriously affected by condensation.
On bigger rigs a lot of the components are mounted separately, which means there's the possibility that parts can be replaced individually. However components on something like a DJI S900 or S1000+ are likely to be more expensive.
Water may cause unseen damage
If your drone was a self build or it's no longer in warranty, you could try taking it apart and drying everything thoroughly and individually. The problem with damage caused by water is that it's not always visible. One thing's for sure, there are no hard and fast rules; one submerged drone might just have a blown ESC, another could be a complete write off. Whatever you do don't try turning it on too soon. You'll either gets clouds of smoke or you'll think everything's hunky dory until it crashes a few flights later. Water damage has a nasty habit of coming back and biting you just when you think that you've got away with it.
Don't take any chances until you're absolutely sure that it has been dried out, checked and fixed. Another crash could have far more serious consequences than injured pride or a shrunken bank balance.
Don't forget, if you need help getting in touch with your retailer for some friendly advice, preferably before you start opening up your drone. You can contact Heliguy's repair centre online or by ringing 0191 296 1024.
There are patented processes out there which claim to waterproof electronics. Liquipel is probably the best known. It's been used to treat mobile phones and tablets and on their website nothing larger than an iPad is mentioned. Because it has to be applied in a vacuum, there's no way you can do this at home. Your drone would have to be sent away for treatment. We haven't tested anything like this ourselves but there are videos in the usual places on the web which claim to show that similar processes do work.
If all else fails and you just want to safely retrieve your drone and at the very least salvage the video for a YouTube moment of fame then you could try attaching a self inflating flotation device. A few seconds after it becomes submerged a gas filled balloon will float to the surface dragging your submerged drone with it. At least you'll be able to locate your wreckage although, as far as I know, each of these gadgets only lifts up to 1kg. A Phantom 3 Pro weighs 1.28kg so, unless you fancy fitting two of them, that idea might not work for your craft.
Although it may be tempting, think twice then double check your drone before flying over water.
It's probably safer but less exciting to avoid flying over water altogether. If the urge is irresistible, make sure that you do a thorough pre-flight check on the aircraft and the area where you plan to fly. Put a freshly charged battery in and make sure you allow an extra safety margin when bringing your craft back home at the end of the flight. Head winds on the return journey will sap the battery and often catch people out. If the onboard computer detects that the battery is at a critically low level, it will land the drone unceremoniously in the drink without giving a second thought about the state of your overdraft.
Alternatively you could try buying the Loon Copter which recently won top prize at the Drones for Good Competition in Dubai. Developed by Oakland University, it takes water in its stride, so to speak. It can land on water, paddle around on the surface or submerge and "fly" around on its side underwater. Once it gets back to the surface it can take off again as if nothing has happened. Brilliant! Problem solved.