How should I proceed with caution if I crashed my drone in the water?

Hi,

Water and electronics and electricity are not a good mix.

The water causes corrosion and provides circuit paths for the electricity which were not in the drone’s operating design and could damage the components. The corrosion starts immediately and is ongoing until it has been properly cleaned away.

First do not try to charge or to turn on your drone and then remove the battery as soon as possible from the drone to minimize further damage.

Then you need to dis-assemble the rest of the drone and clean all the affected parts using Isopropyl Alcohol 99%+ (available from electronics parts stores) to remove all traces of corrosion and water. Do not use "rubbing alcohol" as in some cases this is usually <70% IPA, can contain additives and is not as effective. If you do have to use it, check the label to verify the amount of IPA. The higher the concentration (%) the better.

Here is a link that describes the process. Electronics Water Damage

You might have to replace the battery as it is very hard to recover a battery from water damage.

As always with electronics, especially surface mounted pcb be gentle when handling and especially when brushing away the corrosion. You do not want to remove any components from the board. Also clean any plugs and connectors etc as the water may have got in there as well

Hopefully after you have done all this the drone might possibly work correctly again.

Here is a link to the ifixit guide(s) for repairing your drone that may help UDI U818A

If this process seems too daunting, take your drone to a reputable, professional electronics repair service, experienced in liquid damage repair and ask for a quote for a repair. If you decide to do this, do it sooner than later.