Flying close to water???

[pedz]

I have a Mavic 4 Pro and I want to do hyperlapses of sunrises skimming close to water. Here is an example but in this sequence the drone is 50' to 100' above the water. I'd like to be only a few feet but I have concerns about doing that. Indeed, I'd like to be so low that the collision avoidance from below is red but that seems to halt forward movement while doing a hyperlapse. I haven't investigated this much. On one occasion, after starting a hyperlapse (using course lock), I lowered the craft down until the red warning came on and at that point the craft was stuck. It would not move. I had to stop the hyperlapse, then I could raise the craft up and fly home.

Can others comment on their experiences on flying low over water either while doing a hyperlapse or not -- with and without collision avoidance activated?

Thank you

 

[Cafguy]

Staying a bit high over water is your friend. The movement of the water can sometimes confuse the sensors and you may get inaccurate readings for altitude from the controller.
If you want to fly really low just be prepared. You may have to save the drone because of something it wants to do. Sunset and sunrise are the least desirable times to fly over water.. The glare from the sun bouncing off the water at these times has been known to cause some pretty strange things to happen!
If I were you I would do it... BUT I would get some good water protection from Phantomrain before I did it for sure.
It will save your drone if it goes crazy......

Oh and I have heard that if you send some Blue Bell ice cream to CAFGUY over in Bakersfield Ca. its extra good luck for flying over water !!!!!!!

​

 

[GFields]

Ditto @Cafguy suggestion

 

[RuudF]

I can only give you one well ment advise: DON'T!
There have been hundreds of pilots who have lost their drones flying over water at low altitudes.
As said before the sensors get confused and this effects the ability to maintain a steady flight level, causing the drone to crash.

Always maintain a safe altitude above a body of water.

Ruud

 

[Paul Harvey]

Always maintain a safe altitude above a body of water.

Ruud

What is a 'safe altitude?'

 

[RuudF]

What is a 'safe altitude?'

A safe altitude is when you can see the reflections of the water don't shimmer on the drones surface.
A minimum of 10 meters or 30 feet is my safe lowest flight level, but on a very sunny day with more reflection on the waters surface I will fly a lot higher.

Search YT for videos of hero pilots who fly very low and loose their drone underwater.

Ruud

 

[Paul Harvey]

A safe altitude is when you can see the reflections of the water don't shimmer on the drones surface.
A minimum of 10 meters or 30 feet is my safe lowest flight level, but on a very sunny day with more reflection on the waters surface I will fly a lot higher.

Search YT for videos of hero pilots who fly very low and loose their drone underwater.

Ruud

Thanks!

 

[RuudF]

Thanks!

Also I would advise you to shut of the Visual Positioning Sensors. (VPS)
They can get confused by the surface of the water and give false information to the brain of the drone about the altitude.
Especially when flying over water in a wind still situation, when the water is like a mirror....these sensors find it difficult to mesure the correct distance to the water surface, causing the drone to loose altitude.

Ruud

 

[MS Coast]

Also I would advise you to shut of the Visual Positioning Sensors. (VPS)
They can get confused by the surface of the water and give false information to the brain of the drone about the altitude.
Especially when flying over water in a wind still situation, when the water is like a mirror....these sensors find it difficult to mesure the correct distance to the water surface, causing the drone to loose altitude.

Ruud

There's not universal agreement on shutting off the VPS system when flying over water. I've never found it necessary or beneficial.

 

[RuudF]

So actually what you are saying: there is also no harm in doing so, isn't there?

 

[MS Coast]

So actually what you are saying: there is also no harm in doing so, isn't there?

Well, switching off VPS removes the drone's ability to assess and display it's height above the water and warn the pilot. That might create some harm.

 

[akdrone]

I was about 15 feet over a moving stream so the water was no smooth clear surface and my Mavic 3 Pro flipped over and dove into the water for no apparent reason. I have read several times that 30 feet is a suggested safe height. I have also flow low over nice clear lakes with no problem at all but I will, in the future, refrain from doing that since getting repairs is, for all practical purposes, impossible.

 

[MS Coast]

I was about 15 feet over a moving stream so the water was no smooth clear surface and my Mavic 3 Pro flipped over and dove into the water for no apparent reason. I have read several times that 30 feet is a suggested safe height. I have also flow low over nice clear lakes with no problem at all but I will, in the future, refrain from doing that since getting repairs is, for all practical purposes, impossible.

That's definitely not good. Did you look at the flight logs to try to sort out what caused the problem?

 

[Meta4]

I was about 15 feet over a moving stream so the water was no smooth clear surface and my Mavic 3 Pro flipped over and dove into the water for no apparent reason.

The incidents discussed previously in this thread would have seen the drone descend or fly into the water in a normal flying attitude.
If your drone actually "flipped over" and fell into the water, it was for a different reason which was unrelated to the water or VPS sensors.
The flight data should point to the cause of that incident.

 

[Dronecation]

The incidents discussed previously in this thread would have seen the drone descend or fly into the water in a normal flying attitude.
If your drone actually "flipped over" and fell into the water, it was for a different reason which was unrelated to the water or VPS sensors.
The flight data should point to the cause of that incident.

I have a question for you Meta4
I plan on photographing colourful trees near a lake and want to descend from straight above and hover close to the water. Does going straight up and down pose a risk? I won't be flying low over the water to get to the spot I want to capture the images.
Thanks in advance.

 

[Meta4]

I plan on photographing colourful trees near a lake and want to descend from straight above and hover close to the water. Does going straight up and down pose a risk?

Not if you stop before you hit the water.
How close to the water are you intending the drone to be?
If you are using the wideangle camera, remember everything will appear further away than it really is.

 

[Cashed]

I was flying about a foot over a swimming pool one time and a gust of wind or it caught a reflection not sure but it hit the water. Straight to the bottom it went. I got out about 10 minutes later and of course it was dead. I still tried a fully charged battery just to see what would happen and nothing happened. I sent it to DJI and I was quoted $1200.00 to fix or replace it. I decided against the Repair and they sent it back to me when I got it back. I put it in the back of my SUV and it stayed back there in the box for seven months. I just kept pushing it from side to side and just never took it out. One day, my wife was cleaning out the SUV and asked me what was in the box and I told her it was my drone and she asked what do you want to do with it? I said it doesn’t matter. You can throw it away if you want to she says well let’s see what it’ll do one more time. Let’s see if it will work. I said it won’t work. I went and got a battery put it in the drone and it has flown perfectly ever since and that was two or three years ago. All it needed was to dry out. The battery that hit the water also dried out and Worked just as good as my other ones.
I’m sure saltwater would have been a different story.

 

[Dronecation]

Not if you stop before you hit the water.
How close to the water are you intending the drone to be?
If you are using the wideangle camera, remember everything will appear further away than it really is.

I will be using the wide angle and will hover about six feet above the waters surface. If I move sideways a few feet, will that pose a problem. I will head straight up again to about 50 feet to clear the lake...

 

[Cafguy]

The reflections causing problems with your sensors thing is not too common BUT not too rare either, there is no way to predict how your sensors will react to the light refraction. The only thing you can do is just watch closely and be ready to do your best to counter act what the drone does. I have been over water during sunset and had no problems at all..Your flight may vary.

 

[Meta4]

I was flying about a foot over a swimming pool one time and a gust of wind or it caught a reflection not sure but it hit the water.

A gust of wind can't send your drone down into the water.
Neither can a reflection.
Did you ever have your flight data looked at to see what it showed?