What did I do wrongly? :Taking off and landing from sailing boat

[fcefalu]

Hi folks,
I'm enjoying some European summer holiday days and today I was sailing with friends in Sicily and decided to give it a go to my mavic to try to take some nice sailing footage... BUT something went wrong since the 1st second from taking off and it's just a case if I still have my mavic, I seriously thought I was going to lose it in the deep Mediterranean Sea! Let me tell you the facts so maybe someone more experienced than a newbie like me can enlight me on what I did wrongly.
The facts : 1) after checking that everything was in order I took off from a flat surface of the boat, the boat was moving I would say at 1mph, almost still but still moving... The mavic didn't take off as usual, I was expecting it to hover about 1 meter height and then to take manual control of it... BUT at the auto take off the drone went immediately up in the air about 3 meters, almost hitting the sail and I promptly tool control of it and pushed it high in the sky to avoid collisions... I Still don't know why this behaviour... What am I missing?

2) after over 10 minutes of perfect fly, track mode and manual flight, I started thinking about landing well in advance compared to my usual as I had the feeling that something could have gone wrong... My fears became real when I realised that was very difficult or close to impossible to manual landing on a (very slow) moving boat... Hence i called help from the crew and asked a friend to get ready to grab the drone manually in the air... I understand it shouldn't be a standard procedure but thought it was the safest... I had about 40% battery by then when I started to approach the boat slowly for a "in hand" landing. Here the troubles started, first of all the drone wouldn't get closer to the boat at human height, was not moving forward at all when at 2 meters height, while was answering to commands if I was pushing it high let's say 7/8 meters. After a couple of failed attempts I realised I should have pushed the drone few meters ahead of the position where my partner was ready to grab it, hoping to get it right at a certain point... Tried several times to fly the drone about 1 meter higher than the head height of my partner but drone was not moving forward, remaining about 4/5 meters ahead.
Meanwhile battery was at about 25% and the bip bip coming from the remote was not helping keeping the nerves calm.
Eventually I decided to approach the boat from the side , flying parallely to the boat and hoping that a lateral push would have pushed the drone in the right position for us to grab it. Eventually this worked out, not without stress and fears, my mate managed to grab it from behind at the first attempt, I tried to turn the mavic off but surprisingly the propellers didn't stop spinning, actually increased speed... Tried forse a good 40 seconds which seemed endless, also tried to turn the drone off from the battery, but unsuccessfully, all of a sudden after 40 seconds with me pushing the levers down and inside, the motor went off and I caught some relief...

Lesson learned : don't fly your drone out of a boat... High risk of losing it....

But I'm still wondering what did I do wrongly, why the drone was not approaching the boat nor answering to my commands promptly...

Any tip? What did I do wrongly?

Thanks for your help

Frankie

 

[newnan3]

Did you have the downward facing sensors turned on?

Why not just stop the boat ?

 

[fcefalu]

Did you have the downward facing sensors turned on?

Why not just stop the boat ?

Boat was stopped... BUT in open sea it is never still....

 

[Flawless]

Few mistakes on your part.

1. Downward sensors turned on.

2. Launching from front of the boat while it was moving (1mp/h is just under half a meter per second).

3. Tried running before you can walk - you tried to learn multiple things (all of which potentially fatal to your drone) at once.

Hand launch and catch from land where, you don't have to worry about additional variables like sails, rigging, and boat movement, etc.

Practise flying over water and learn to switch off downward sensors mid-flight.

Practise the above when switching into sport mode, because you will need to do it at some point.

 

[Gary cato]

sounds like you had all the obstacle avoidance and landing sensors on the high rotor speed as you caught it was because it was detecting ground and trying to pull up.

Turn off landing protection and this is not an issue even with VPS left on.

Turn off obstacle avoidance it has a bigger range than many people think, it has to, as it has to have time to stop.

The moving boat will confuse it even further causing it to struggle to know what it should be doing.

This is for more experienced flyers than even me to be honest and it sounds like you need a bit more practice and read up on the sensors on the threads here there are hundreds.

If you don't understand how all those sensors work on the drone really you should not attempt that stuff until you do. .

If you do understand them all then i am sure others more experienced will tell you how it is done or not done.

 

[jbar55]

I just want to say how helpful this is. I've had my Mavic for a week (first drone), and have been loving it. Next week I want to try launching it from a Pontoon Boat on a Lake, so I've been reading up on the sensors, etc. I've had no problem hand catching mine on land... At least with the Pontoon there is a lot of space, but I'm still a little nervous.

 

[stratos]

a tip is that even if you have the sensors on, you could try to make it approach flying backwards to the sensors doesnt detect you.
Then stretch your arm and grab it from the belly, and then stop it from the remote.

I dont really like hand catching but its easy if you practice.

 

[dwallersv]

Okay, I haven't done it, but from what I've gleaned from a bunch of different threads here and over on the DJI forum, to fly from a moving platform:

• Disable Obstacle Avoidance
• Disable Visual Positioning System
• Fly using Follow Me mode -- only fly when excellent GPS on both aircraft and smart device connected to RC; make sure you're thoroughly familiar and experienced with FM mode on the ground first
• Hand launch and retrieve, preferably (much) with another person

Not everyone agrees with the Follow Me mode portion, and there are some limitations, but it also has been used very successfully by several people as well. So, it seems to me that this is a reasonable formula for making this as easy, controllable, and safe as possible when suitable.

 

[Lapeer20m]

Was the launching surface metal?

 

[fcefalu]

Was the launching surface metal?

No

 

[fcefalu]

Thanks everyone for the inputs, I agree with you all I took some risk as I should have mastered better the controls before adventuring myself in such a flight... The video outcome was beyond amazing but I wouldn't repeat it until I'm 100% confident with what I am doing

 

[GerdS]

Moving boats for takeoff and landing are one situation where it would be a big benefit having a selectable Atti mode, as this would prevent the drone from holding GPS position, what looks as "unexpected behaviour" from an unexperienced pilot's view. Most things are already said, just ensure that you take off at the stern of the boat with no obstacles behind you place. And best practice for landing is to approch from behind or fly in parallel to the boat and reduce distance until it can be grabbed out of the air. Ensure that optical sensors and landing protection are off and it is also a good idea enabling the CSC command to work always, so you can shutdown the motors after grabbing it, in case they don't stop on their own.

 

[panotaker]

Did you get that landing on video?

 

[fcefalu]

Did you get that landing on video?

The worst 4 minutes of my "pilot" experience!

 

[panotaker]

I think you should put up the footage of your landing to show people what not to do, plus it will be pretty funny to watch.

 

[SONIC]

My thoughts:

Do not use auto takeoff in this situation, you see why. The drone will take off and try to stay in the same GPS spot it took off in. If the boat is moving the boat will run into the drone.
Take off manually and fly from the ground/boat up. Or as mentioned take off from the stern if moving forward. But I still prefer manual, I like to be in control.

Reading your account is seems like an obstacle avoidance problem. Was the remote screaming at you?

 

[Mako79]

In all seriousness.. you should use a large fishing net to catch on a boat. The props will stop immediately..

 

[fcefalu]

In all seriousness.. you should use a large fishing net to catch on a boat. The props will stop immediately..

Thought so as ultimate resource... Although i Think I would have damaged the gimball. . I would say without collisions sensors on, I woukd have avoided 85% of the troubles/difficulties