The answer, in my experience is... yes, no, kinda, and "but for how long?".
A few years back my hometown was experiencing record rainfall. Roads were washed out, dykes were being breached, communities were flooded, fields were awash and rivers and creeks were bursting their banks.
During a brief break in the downpour, I hurried to a local river hoping to get some great video.
Well, I flew a bit too close to the water. The next thing I knew, my Mini gave me a gimbal warning, did a little spin, and went for a swim immediately sinking out of site!
What a bummer. But, I knew exactly where the drone was, 10 feet from the bank of a raging river.
A week or so later I returned. The river had slowed and returned to a normal level.
Lo and behold, I could see the Mini several feet below the surface.
I jury-rigged a hook on the end of a long stick and managed to retrieve the drone.
Would it fly once it dried out?
I removed the battery and sd card, put the drone in a warm place, and hoped for the best.
Was there still a video on the sd card? I could hardly wait to find out.
Not only did I have a video of the drone misbehaving and hitting the water, but the camera also kept recording as the Mini sank to the bottom of the river.
There were almost 40 seconds of underwater video!
I dried the drone for a couple of days before inserting a fresh battery and hitting the power button. The power lights came on but there was no familiar chirping or movement from the gimbals or propellors.
The battery that was in the drone when it went for a swim seemed to be waterlogged so it was right off.
The motors faired no better.
All 4 motors, plus those in the gimbal, were completely seized. Their tiny magnets had been busy collecting dust-sized bits of ferrous metal all week. There was no way to clean them, believe me, I tried.
The final verdict:
- The camera and circuitry may be very water resistant
- The gimbal may be susceptible to a raindrop or two.
- The motors are vulnerable to some ferrous metals suspended in "freshwater"
In conclusion, if the drone was retrieved right away I have no doubt it would have survived.
Bottom line, I don't recommend flying in questionable weather. Using your drone as an underwater ROV is a bad idea too.