P3 standard:

In the Go App you can enter new home-point: aircraft position or transmitter position...

When updating home-point to the transmitter position the drone will RTH to that position.

What happens when the transmitter keeps on moving while the bird is returning home?

Will it follow the moving transmitter or return and land at the point where the transmitter-home-point was activated?

Planning to fly my P3S from my boat, so that's the reason for my question...

All comments/experience on flying over watter is welcome! (and yes, I'm aware of the risk, but trying to minimize that risk!)

It will RTH to the location where the controller was when you reset.
But if you are out on a boat you shouldn't be letting RTH land for you and you would definitely want to cancel RTH and resume control and hand catch the Phantom.
Plus if you are out on a boat, you probably don't want to be flying so far away that you lose sight of the Phantom.
Out at sea it's a very unforgiving environment.
Make sure you are familiar with your Phantom and how it all works before getting adventurous.
And definitely learn to hand catch on land before trying it on a boat.

The best method is to enable dynamic home point. This feature continuously updates the home point to the position of the mobile device. Ideal when the mobile device keeps moving from one location to another.

Not sure if it's available in DJI Go, but it is available in Litchi.

OrlyP Posted at 2016-8-11 20:23
The best method is to enable dynamic home point. This feature continuously updates the home point to ...

DJI Go has something it calls Dynamic Home Point but it's not dynamic at all.
It just resets to the current location of the controller.

Here is the worst case scenario:

When I set a home point at x the (sail)boat will keep on moving away from point x...
Lets say the boat is 300m away from point x and the drone is still close to the boat...
When I lose rc signal with the drone close to the boat (chance is small but existing) the drone will RTH to point x and even fly further away from the transmitter.
So instead of regaining signal, the signal will get wors because the drone gets further away.
About the Dynamic Home Point: does it update frequently by itself (like every few seconds)? Or only when tapping the button to reset the home-point?

labroides@yahoo Posted at 2016-8-11 12:09
It will RTH to the location where the controller was when you reset.
But if you are out on a boat yo ...

I'll be sailing my boat on a big lake first, not at sea. And in the evening when winds become moderate to calm.
Handstarting and cathing is no problem than.
Off course I should cancel rth and resume control for handlanding... But that's only possible when the Phantom comes closer to the TX when in RTH-mode. While the boat is always moving there could be a chance that the drone flies even further away from the boat towards the latest home-point, and not getting back in range for RC-signal.
Again... it's all worst case scenario. I will keep the drone close to the boat for video and pics. Small chance anything will go wrong. Just want to be prepaired when things go wrong on the rc-signal.

hayen.dominique Posted at 2016-8-11 21:32
Here is the worst case scenario:

When I set a home point at x the (sail)boat will keep on moving aw ...

If Litchi has a real dynamic home point (I haven't used it so can't comment) it will probably update every couple of seconds or so.
DJI's won't.

But another stategy would be to:
1.  Change your loss of signal settings from RTH to hover
2.  Frequently reset your home point to either the current R/C location or the current Phantom location and so keep the distance the Phantom would be from the boat if you did lose signal.

OrlyP Posted at 2016-8-11 12:23
The best method is to enable dynamic home point. This feature continuously updates the home point to ...

Have to sort it out in de Go App.
But Litchi sounds like a better option if it is really dynamic home point and switching constantly while moving.
That's the only garantie that the drone will always fly towards the boat in case of signal loss.
A motorboat can easily and fast be directed towards the position of the drone.
But a sailing boat under sail takes some time to get back.
Especially when the captain of the boat is also piloting the drone! ;-)

OrlyP Posted at 2016-8-11 12:23
The best method is to enable dynamic home point. This feature continuously updates the home point to ...

Confirmed by DJI-Ken: it does not update continuously in Go App, only manual.

hayen.dominique Posted at 2016-8-11 19:52
Have to sort it out in de Go App.
But Litchi sounds like a better option if it is really dynamic  ...

Question. How does drone update the home point if the transmitter is out of range?

stuka Posted at 2016-8-11 21:04
Question. How does drone update the home point if the transmitter is out of range?

I suppose it is not updating anymore in that case and activating rth-mode to last updated home-point.
Once the signal is back it will update again the new homepoint if the rx is moving.

hayen.dominique Posted at 2016-8-11 23:31
I suppose it is not updating anymore in that case and activating rth-mode to last updated home-poi ...

Are you planning to zip off out of sight to film distant things ... or just buzz around your boat anad ather stuff close by?
If you are nearby, none of this should matter much because IF you lost signal and had the Phantom set to hover if signal is lost, it's not going to be far away anyway.

ps  I fly over water a lot and have never lost signal except for going so far I was out of range.

labroides@yahoo Posted at 2016-8-11 19:45
If Litchi has a real dynamic home point (I haven't used it so can't comment) it will probably upda ...

Hi,
How can I set RTH to hover ? It is the best choice for any RTH problem.

eurasia29 Posted at 2016-8-12 04:56
Hi,
How can I set RTH to hover ? It is the best choice for any RTH problem.

Look in your MC settings .. under Advanced Settings
There are 3 options for RC Signal Lost

RTH is the best choice in most situations but for some situations Hover or Landing might be appropriate.

It will RTH to the location where the controller was when you reset.

This is untrue and misleading to a newbie who happens to read it.  Home point is set to the coordinates of the drone, not the RC.  In fact, there's no GPS in the controller, and you don't have to have one in your device to fly either.  You don't have to have a device to fly and use RTH either.

AG0N-Gary Posted at 2016-8-12 13:02
It will RTH to the location where the controller was when you reset.

This is untrue and misleading  ...

Not quite true, if your device does have a GPS then, like Follow Me, there is an option in the menu to set the Home Point to the position of the controller, not the aircraft. And the OP even knew that. What he was asking was, does the Home Point keep updating to the current position of the controller continuously, and the answer is no.

It follows the devices attached GPS signal the controller has no location ability

If close to shore you could always take off from solid ground and that would be the RTH point, would need a bit of planning maybe, but would give some peace of mind should things go wrong.

labroides@yahoo Posted at 2016-8-11 15:53
Are you planning to zip off out of sight to film distant things ... or just buzz around your boat  ...

Hi,

I will keep the drone close to the boat. So yes, signal loss will be most unlikely and set hover for signal loss seems the best option.
Next weekend I'll give it a shot from my boat with the Go App.
However switching over to the Litchi App seems a better option because of the real dynamic home-point updating, but I'm short in time to get familiar with the app.

eurasia29 Posted at 2016-8-11 20:56
Hi,
How can I set RTH to hover ? It is the best choice for any RTH problem.

When you are flying far away and out of sight I guess RTH is the best option when signal is lost!
In this topic we are discussing best option in case the transmitter is constantly on the move with drone near by. Here the best option is to let it hoover when signal gets lost (avoiding the drone will fly back to the home-point far away)

I ordered a Sunhans 2Watt booster for the 5.8Ghz transmitter signal. This will surely fix the signal issue on my P3S. Don't get me wrong, my signal is ok, according DJI-specs.
But I see a lot of problems with other P3S signals, depending on environment and tx orientation. I guess my P3S is no different from those!

Geebax Posted at 2016-8-11 23:46
Not quite true, if your device does have a GPS then, like Follow Me, there is an option in the menu ...

Please note that I was not responding to the OP, but to a comment from someone else.

AG0N-Gary Posted at 2016-8-13 15:46
Please note that I was not responding to the OP, but to a comment from someone else.

I realise that, but the OP said in his opening post:

'When updating home-point to the transmitter position the drone will RTH to that position.

What happens when the transmitter keeps on moving while the bird is returning home?"

To which Labroides replied:

'It will RTH to the location where the controller was when you reset.'

In that reply he was answering that the aircraft will RTH to the position where the transmitter was when he last set the home point to the transmitter's position. You indicated that the answer was wrong, in fact it was quite correct. No one was talking about setting the home point to the position of the aircraft.

Sorry, I didn't read it that way.  I think the point is across to whoever reads the thread now anyway.  Tnx.