Over water risk reduction

[DDDDMF]

I am aware of the risks of flying over water and the reflection issues with the sensors. But does increasing the altitude lower the risks any? I am talking about 300 feet to 400 feet. Not 3 feet to 4 feet. Thanks in advance.

 

[Lastrexking]

I am aware of the risks of flying over water and the reflection issues with the sensors. But does increasing the altitude lower the risks any? I am talking about 300 feet to 400 feet. Not 3 feet to 4 feet. Thanks in advance.

Absolutely - I’m no expert but I think the sensor issue is the drone starts to auto land when it gets so low, then before you know it it’s a submarine. Personally, I would never go lower than 10 metres over water.

 

[scro]

The downward sensors only work for relatively low altitudes (max 30m/100ft). Above that the drone relies on GPS and barometer, which are not affected by water underneath the drone so flying at 30m or higher you should be guaranteed to to not be affected by erroneous position sensing via the VPS.

My personal experience from multiple flights over water (sea, rivers, lakes) have been issue free. I've usually kept the drone at least 2m above the water, but have on some occasions gone lower, down to 0.5m.

 

[StantonZ]

The downward sensors only work for relatively low altitudes (max 30m/100ft). Above that the drone relies on GPS and barometer, which are not affected by water underneath the drone so flying at 30m or higher you should be guaranteed to to not be affected by erroneous position sensing via the VPS.

I would have been fine if you had stopped after the first paragraph (my edit above)!
I flew over water as recently as yesterday, and agree that it is much the same as land (from the drone's perspective)...as long as you keep it above 100 feet or so. Even better, you tend to get better distance/range over water without those pesky trees/buildings/etc.

 

[scro]

I would have been fine if you had stopped after the first paragraph (my edit above)!

I was just giving some detail of my personal experience I know some people haven't had the same level of success with flying close to water and I'm fairly sure the OP is also aware of these cases as they did say they were aware of the risks of flying over water.

In short, flying less than 2m above water doesn't guarantee your drone will end up diving, uncommanded, into the water, but the risk IS significantly higher than if you fly more than 30m above the water.

 

[passedpawn]

Can the auto-landing be turned off?

 

[scro]

Can the auto-landing be turned off?

Not formally, in the Fly app. You can tape over the sensors which disables the VPS, and hence the auto landing.

 

[passedpawn]

Not formally, in the Fly app. You can tape over the sensors which disables the VPS, and hence the auto landing.

I have a mavic 2. So that's the DJI GO app. Wonder if it has the same limitation.

 

[Meta4]

I am aware of the risks of flying over water and the reflection issues with the sensors. But does increasing the altitude lower the risks any?

Your downwards sensors can't lock onto any pattern or features on the water surface so can't help with position holding and may not pick the surface to give an accurate distance measurement.
But water isn't a magnet that will suck the drone downwards.

I am talking about 300 feet to 400 feet. Not 3 feet to 4 feet.

You do realise that the sensors only work at up to 10 metres?

 

[boblui]

The only risk of flying over water is that if the craft falls out of the sky for any reasons, you wont be able to retrieve it so flying higher will not reduce the risk.

Drones going into the water by themselves because of the bottom sensors being confused by water reflection or whatever is one of the most widely spread misinformation in this community. Out of the many water crash reports I have seen here, the flight logs provided by the pilot indicated that NONE was due to sensors being fooled by water.

This is my M2P descending to water surface. The Mini behaves in exactly the same way because the same type of sensor ( infrared proximity sensor ) is used.

As indicated by the VPS figure at the bottom of the screen, the infrared sensor was able to detect the distance from the water surface accurately. When the drone got to a height of 1 meter over the water surface, the drone actually RESISTed descending further even when full throttle-down input was applied. This is in direct contradiction to the rumour.

Of course if the pilot insists to get the drone wet by keeping the throttle stick fully down after 2 seconds are elapsed, the drone will do so. There have been multiple cases in which the pilot claimed that the drone went into the water by itself but the flight log indicated that it was actually commanded by the pilot.

 

[scro]

@boblui My experience with flying over water aligns with yours. I did once manage to get the proximity sensor pick up the riverbed rather than the water surface, so I could get closer than 0.5m to the water without initiating a landing.

@Meta4 The sensors work at up to 30m, but are most reliable at 10m or less. Pg15 of manual (rev 1.2):

 

[FlyBackOU812]

I can tell you for a fact you have nothing to worry about over 20ft and thats being generously cautious. I litterally have hundreds of flight hours over water and have never had the sensors create any problem for me. The aircraft doesn't react to water any differently than land in my experience, which is a lot. These are from this past summer with Mavic Mini 1

 

[FlyBackOU812]

 

[FlyBackOU812]

 

[skipweeks]

I am aware of the risks of flying over water and the reflection issues with the sensors. But does increasing the altitude lower the risks any? I am talking about 300 feet to 400 feet. Not 3 feet to 4 feet. Thanks in advance.

I have not had that problem. Here I am about 18” over a stream.

 

[Rodders]

Be safe don"t fly over water

 

[scro]

Be safe don"t fly over water

Be safe don't fly over water ?‍

 

[Ridge Rider]

On your video clip of the ocean, if you used a filter, what was it? Liked the deep blue waters and sky line.

 

[DanMan32]

I've flown over water and I usually don't have a problem, though I'm usually at least 30ft up.

I did have a wierd issue once though where my M2Z from visual observation seemed to circle around, sort of a toilet bowl effect. It was a windy day, though not so windy that the M2 couldn't handle. I figured that the water currents were causing a treadmill effect with the VPS, but when it detected GPS deviated from the expected hover, it corrected and moved back.

Fearing a serious problem was imminent, I hit RTH which was flawless, other than a few phantom OA detection.

Logs didn't seem conclusive, other than showing the uncommanded circling.

 

[Michael Ainsworth]

Can only speak from my experience.
Fly original MP with downward sensors off and the Mavic Air2. Fly both down low over water, but I don’t fly fast or far when low.
My aim is to get decent footage of specific scenes then move out.
I take it slow and steady always in LOS, don’t rely on looking at the screen as you can lose sight of drone and spatial awareness quickly.
Never had any situation where they would want to land.