Question about flying over water and diving

[mikemoose55]

dwolf
Sorry for ruffling your feathers, wishing blue skies and calm winds your way.
mikemoose55

 

[msinger]

I suspect that the software won't go into landing mode if there is sideways momentum.

It actually does if the throttle is in the full down position. I've reviewed many flight logs where that happened.

Partial throttle down (or no throttle down) causes the Mavic to ascend. Full throttle down for about 1 second causes the Mavic to switch to Forced Landing mode.

 

[old man mavic]

I figured it would be easier and better if I just put all this into one post instead of replying to all that answered. First off, thank you all that gave me more insight to what the sensors will and will not do. I prefer to hear about real world scenarios while still understanding manufacturer do's and don'ts and carefull's. What I have learned so far is that the sensors may or may not save me if I make a MISTAKE. I can live with that and make a decision on whether to fly like I had planned or try to do like knewt suggested, which sounds like a less dangerous idea to get basically the same thing. So, after all the input I have decided that I will try it if the land testing works out and will decide then whether to try it my original way or knewts way.

Now, I probably should give an apology to Omm and mikemoose55. I now realize that you both were either concerned about my flying ability or the M2P or both. I have a lot of practicing to do over the next few months and I consider any mistakes I make are on me. I'm not really looking for something to save me from myself but I thought that if the sensors would work/ may work, then they may be a POSSIBLE backup to any mistakes I may make. All I was looking for is how the sensors work in that type of situation if anyone knew. Then, I would make a decision on whether to fly in that manner. So, I am sorry I took your posts the wrong way. I already plan to practice, practice, practice and learn, learn, learn. I promise you that is the first thing I'm doing. Then I will do the same on land for the type of flight and once I am satisfied that I can do it then I will take to the water. So, if I turn the Mavic into a boat you are welcome to tell me "I told you so" and I will still invite you to the funeral.

thanks for your reply just trying to help happy flying and learning

 

[dwolfe002]

dwolf
Sorry for ruffling your feathers, wishing blue skies and calm winds your way.
mikemoose55

It's really not a problem. That's why I apologized. Not long before your post I had a relative tell me I couldn't do it and I would need a year of flying before I should even think about trying something that stupid and I guess I was just tired of hearing that. Really, the sensors is the part of the flight I have in my head that I didn't and maybe still don't fully understand and I will have to fly it over ground to find out what I can from that. So, don't worry about ruffling these feathers. I'm lucky just to have enough left to get ruffled.

Take care and happy flying!

 

[dwolfe002]

thanks for your reply just trying to help happy flying and learning

No problem at all. I'll be reporting back after testing and performing the flight so that everyone will at least have an idea of whether it can be done or not. If it can, then I will possibly telling people that ask me the same thing you told me and maybe add in instructions to bring an extra pair of shorts with them.

Take care and happy flying!

 

[Elude]

Full throttle down for about 1 second causes the Mavic to switch to Forced Landing mode.

Sounds about right when I hand catch it. It hesitates then slowly goes down.

 

[FormerMember07122019_2]

I think the water clarity can have an effect on how the vision sensors operate. I have a 1/2 acre pond that I have flown my M2P over a handful of times with no issues but it is not that clear due to algae, etc. I have seen videos of folks flying over backyard swimming pools with crystal clear water and the Mavic 2 has exhibited some very strange behavior.

 

[dwolfe002]

I did some testing at the park today and found out that that what most of you said was true. The Mavic 2 may or may not sense the ground. None of this testing is scientific. Just me trying to watch while having control of the aircraft. What I did today was go full speed forward and down from around 40ft and found that sometimes the Mavic 2 would sense the ground and pull up when I got somewhere around 5ft above the ground. Finally stopping completely at around 2 feet from crashing. I did this around 20 times and the sensors kicked in probably 30% of the time. Then I turned the sensors off and tried it with no help from anything but me. I probably tried it around 7-10 times and crashed once. The strange thing is that I didn't crash coming in on the dive. After diving and stopping the dive while at the same time continuing forward at full speed the entire maneuver the Mavic 2 all of a sudden went to the ground. Now it was only at about a foot to a foot and a half off the ground at the time and just plowed in maybe 50 ft after coming out of the dive. So I'm not sure what happened there but I imagine that if I had pulled out of the dive earlier I probably wouldn't have crashed but that testing will have to be for another day. Another thing I just thought of. It was partly cloudy out today and most of the time you couldn't see the sun but the sensors seemed to work better when I was flying somewhat toward the sun. Maybe a 45 degree angle. I can't really remember a time the sensors worked flying away from the sun at about the same angle. That really doesn't make much sense to me. So in the end, I have some questions still. Next time I will take a notebook so I can keep better track of what happens in different test but first I have to replace my props and clean up the Mavic 2. I really didn't think I would see so many different things happen.

One other note...Old Man Mavic and Mikemoose55...now you both are free to give me any s@&% you want to and I will not have a word to say. I crashed!

It will be at least 5 days before I get out again. I just don't understand why all this rain started falling after I got my M2P.

 

[mikemoose55]

I did some testing at the park today and found out that that what most of you said was true. The Mavic 2 may or may not sense the ground. None of this testing is scientific. Just me trying to watch while having control of the aircraft. What I did today was go full speed forward and down from around 40ft and found that sometimes the Mavic 2 would sense the ground and pull up when I got somewhere around 5ft above the ground. Finally stopping completely at around 2 feet from crashing. I did this around 20 times and the sensors kicked in probably 30% of the time. Then I turned the sensors off and tried it with no help from anything but me. I probably tried it around 7-10 times and crashed once. The strange thing is that I didn't crash coming in on the dive. After diving and stopping the dive while at the same time continuing forward at full speed the entire maneuver the Mavic 2 all of a sudden went to the ground. Now it was only at about a foot to a foot and a half off the ground at the time and just plowed in maybe 50 ft after coming out of the dive. So I'm not sure what happened there but I imagine that if I had pulled out of the dive earlier I probably wouldn't have crashed but that testing will have to be for another day. Another thing I just thought of. It was partly cloudy out today and most of the time you couldn't see the sun but the sensors seemed to work better when I was flying somewhat toward the sun. Maybe a 45 degree angle. I can't really remember a time the sensors worked flying away from the sun at about the same angle. That really doesn't make much sense to me. So in the end, I have some questions still. Next time I will take a notebook so I can keep better track of what happens in different test but first I have to replace my props and clean up the Mavic 2. I really didn't think I would see so many different things happen.

One other note...Old Man Mavic and Mikemoose55...now you both are free to give me any s@&% you want to and I will not have a word to say. I crashed!

It will be at least 5 days before I get out again. I just don't understand why all this rain started falling after I got my M2P.

dwolf
I not trying to beat you up or get over on you. Simply trying to share some of the little experience I have.
Please consider this...there are a plethora of landing pads available for Mavic drones. There are two basic reasons these items even exist.
No 1 is to give the drone a clean debris free landing and take off platform. The Mavic sits quite low normally and even neatly cut lawns can interfere with the rotation of the props. Stones dust twigs etc are also a major issue.
Secondly and more importantly you will notice the landing pads are high visibility targets like the image here.
This presents to the sensors on the Mavic a high contrast difference from a piece of mono color black top or nondescript common green lawn. The sensors on the Mavic are not that sophisticated such that sensors can differentiate such targets thus the bold contrasting colored landing pads. I my self use a piece of yellow coro-plast sheet about 30 inches square with a black tape cross to offer solid contrast to the sensors. It works great my mavic sees it nicely and using precision RTH it hits it every time.

When you are over water the surface the mavic is attempting to read is no1 dynamic changes with every inch and angle from which the Mavic views it not to mention ripples waves and the influence from downdraft. Secondly the water is reflective sparkles, diffuses light and more things I know. Think of it as trying to get your Mavic to recognize a sheet of glass that pitches and moves, reflects, etc . To expect the sensors to read and understand this condition is just not a realistic and if you depend on this to save your Mavic in a rapid descending mode my guess is you will be mostly disappointed with the result.
I am not totally sure but in the tons of stuff I have read from DJI or Youtube or other sources I have read warnings about sensors poorly understanding surfaces like water or snow covered ground or landing areas that offer no relative contrast.

Please understand I am not intending to beat you up but just trying to portray the sensors on the Mavic as poor operators when the viewed surface offers no contrast or differential for the sensors to correctly evaluate.
mikemoose55

 

[dwolfe002]

dwolf
I not trying to beat you up or get over on you. Simply trying to share some of the little experience I have.
Please consider this...there are a plethora of landing pads available for Mavic drones. There are two basic reasons these items even exist.
No 1 is to give the drone a clean debris free landing and take off platform. The Mavic sits quite low normally and even neatly cut lawns can interfere with the rotation of the props. Stones dust twigs etc are also a major issue.
Secondly and more importantly you will notice the landing pads are high visibility targets like the image here.
This presents to the sensors on the Mavic a high contrast difference from a piece of mono color black top or nondescript common green lawn. The sensors on the Mavic are not that sophisticated such that sensors can differentiate such targets thus the bold contrasting colored landing pads. I my self use a piece of yellow coro-plast sheet about 30 inches square with a black tape cross to offer solid contrast to the sensors. It works great my mavic sees it nicely and using precision RTH it hits it every time.

When you are over water the surface the mavic is attempting to read is no1 dynamic changes with every inch and angle from which the Mavic views it not to mention ripples waves and the influence from downdraft. Secondly the water is reflective sparkles, diffuses light and more things I know. Think of it as trying to get your Mavic to recognize a sheet of glass that pitches and moves, reflects, etc . To expect the sensors to read and understand this condition is just not a realistic and if you depend on this to save your Mavic in a rapid descending mode my guess is you will be mostly disappointed with the result.
I am not totally sure but in the tons of stuff I have read from DJI or Youtube or other sources I have read warnings about sensors poorly understanding surfaces like water or snow covered ground or landing areas that offer no relative contrast.

Please understand I am not intending to beat you up but just trying to portray the sensors on the Mavic as poor operators when the viewed surface offers no contrast or differential for the sensors to correctly evaluate.
mikemoose55

mikemoose55... I wouldn't bother me at all. I crashed during testing and I'm the one that leveled out probably 1/10 of a second too slow. If I had done it a little quicker everything may have been ok. I didn't have the sensors on when I crashed. I had turned them off to see if I could do it without them at all. I did it but it came out of the dive a little to close to the ground I think. Since all the sensors were off it was just practice for doing it without any possible help. Since I didn't have any sensors on, I wasn't expecting anything to happen because the field is flat and I was just watching it fly forward very close to the ground and then it just took a quick dive. So, I guess I'm going to have to start back at the beginning and make sure I come out of the dive around 4 to 6 ft. That way I'll at least have a chance to increase altitude if it decides to take another dive. I'm going to check and see if the video was on at the time or not and if so I will try to post it here if I can figure out how. I was so worried about the test and kept forgetting to turn on the video.

Take care and happy flying!

 

[Phantomrain.org]

Phantomrain Post:

We have not yet had a chance to test the Mavic 2 Sensors however I found the old footage of the Phantom 4 Pro Released 2016 testing out the sensors and the Original Wet Suit.

You can hear the sensors pick up the waves and stop the drone before advancing.
There are those who talk the walk , but we try to walk the plank and test the limitations of the drone to failure.

This footage is is before we created the Rescue Jackets for the Phantom drone. We used these fish string bobbers that failed us twice.

Once the ice melts and the lake is back we will be taking the Mavic 2 thu the same sensor tests.

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

 

[Phantomrain.org]

I did some testing at the park today and found out that that what most of you said was true. The Mavic 2 may or may not sense the ground. None of this testing is scientific. Just me trying to watch while having control of the aircraft. What I did today was go full speed forward and down from around 40ft and found that sometimes the Mavic 2 would sense the ground and pull up when I got somewhere around 5ft above the ground. Finally stopping completely at around 2 feet from crashing. I did this around 20 times and the sensors kicked in probably 30% of the time. Then I turned the sensors off and tried it with no help from anything but me. I probably tried it around 7-10 times and crashed once. The strange thing is that I didn't crash coming in on the dive. After diving and stopping the dive while at the same time continuing forward at full speed the entire maneuver the Mavic 2 all of a sudden went to the ground. Now it was only at about a foot to a foot and a half off the ground at the time and just plowed in maybe 50 ft after coming out of the dive. So I'm not sure what happened there but I imagine that if I had pulled out of the dive earlier I probably wouldn't have crashed but that testing will have to be for another day. Another thing I just thought of. It was partly cloudy out today and most of the time you couldn't see the sun but the sensors seemed to work better when I was flying somewhat toward the sun. Maybe a 45 degree angle. I can't really remember a time the sensors worked flying away from the sun at about the same angle. That really doesn't make much sense to me. So in the end, I have some questions still. Next time I will take a notebook so I can keep better track of what happens in different test but first I have to replace my props and clean up the Mavic 2. I really didn't think I would see so many different things happen.

One other note...Old Man Mavic and Mikemoose55...now you both are free to give me any s@&% you want to and I will not have a word to say. I crashed!

It will be at least 5 days before I get out again. I just don't understand why all this rain started falling after I got my M2P.

Hopefully my post will stop you from testing it over the water as I had to go way back to find that video testing the sensors

 

[dwolfe002]

Hopefully my post will stop you from testing it over the water as I had to go way back to find that video testing the sensors

I'm afraid I don't understand why that video would stop me from my testing. In that video a Phantom is being used and it is a bit older which means that it is using a different sensor system than the Mavic 2 uses. Your video uses a downward sensor and the way I plan to come in at an angle, close to 45 degrees from a height of around 40 ft., to the water, I think the Mavic 2 will use the front sensor. Not sure how to prove it but it is what I think right now. The flight type will be much different than basically hovering over water. I think all those differences should require a test. The only commonality between that video and my planned flight is saltwater which is a killer in its own right.

Take care and happy flying!

 

[dwolfe002]

I fly over water all the time. Lake Tahoe. Like I mentioned I descend slowly so that I dont over compensate and take the Mavic for a submarine ride. Forward facing obstacle sensors do sometime indicate an obstacle , but that is usually the low hanging sun. I just rotate slightly so that I am not facing directly towards the sun and carry on. I also fly over solidified water (also known as ice) and its a blast flying low and fast! Here is a sample shot in Alaska.

The Mavic is really the Cadillac of the sky compared to "freestyle" drones.

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

BDOG, I was wondering about your altitude. I was very low today flying over land and took a nosedive. What altitude do you usually fly safely over water.

Thanks!

 

[BD0G]

I usually fly at approx 10 feet above water. I have flown lower than that , but its risky for sure. I like to get low landscape shots over the lake and that requires getting pretty low.

The water in Lake Tahoe is 99.994% pure, making it one of the purest large lakes in the world. For comparison, commercially distilled water is 99.998% pure. Tahoe contains roughly 60 parts per million of dissolved matter.

Its Alpine fed water by the snow melt. If I do hit the water there is no salt or brackish water to worry about corroding the electronics. Recovering it will be a nightmare though. Water is way too cold now in the Winter. In summer I could paddleboard out and hopefully spot it. Visibility is insanely clear.

 

[kilomikebravo]

I just don't understand why all this rain started falling after I got my M2P.

That would be....drum roll please....Murphy's Law.

 

[dwolfe002]

That would be....drum roll please....Murphy's Law.

Well, I'm thinking we need a different law.

 

[dwolfe002]

I usually fly at approx 10 feet above water. I have flown lower than that , but its risky for sure. I like to get low landscape shots over the lake and that requires getting pretty low.

The water in Lake Tahoe is 99.994% pure, making it one of the purest large lakes in the world. For comparison, commercially distilled water is 99.998% pure. Tahoe contains roughly 60 parts per million of dissolved matter.

Its Alpine fed water by the snow melt. If I do hit the water there is no salt or brackish water to worry about corroding the electronics. Recovering it will be a nightmare though. Water is way too cold now in the Winter. In summer I could paddleboard out and hopefully spot it. Visibility is insanely clear.

Thanks for the info. Although I don't understand why 1 1/2 feet doesn't work with the sensors off at least now I have an idea how high I may have to pull out of the dive. Next test will be coming out of the dive while traveling horizontal at around 5' with both sensors on and off.

By the way, those are nice videos and pics. I like it.

Take care and happy flying!

 

[CanadaDrone]

I have flown low over water many times (still and running water, clear water, ocean water, etc.) without issues. The drone's altitude is determined by the barometer and I have never seen the drone behave any differently than if it were over land. Flying over water always carries a certain risk though, if something does happen, you are pretty much screwed. I wouldn't recommend flying 6 inches above the surface but a few feet up has never been an issue for me personally.

 

[dwolfe002]

I have flown low over water many times (still and running water, clear water, ocean water, etc.) without issues. The drone's altitude is determined by the barometer and I have never seen the drone behave any differently than if it were over land. Flying over water always carries a certain risk though, if something does happen, you are pretty much screwed. I wouldn't recommend flying 6 inches above the surface but a few feet up has never been an issue for me personally.

I'm kind of thinking it is different definitions of what "low" is. Looks like my next test will probably right between your 3 and bdogs 10. Thanks for the information.

Take care and happy flying!