I upgraded to .900 to take advantage of the ability to set the Active Track speed using the slider in the app.

I tried it for the first time this evening on a rowing boat.  Drew the box round the subject, put the slider on max to 15 m/sec., pressed trace and hit go on the green box.  Subject moved off not going any real speed, but Mavic lagged behind badly.  Wouldn't hit anywhere near 15m/sec, more like 1-2m/sec.  Resulted in the boat moving away and the Mavic not keeping up.

Am I doing anything wrong or have I missed something here?

I'm hoping someone chimes in with some helpful hints because I have experienced the very same, and like you am wondering what I'm doing wrong, or if that's just how it is.

If I understand your question correctly, you want the Mavic to circle around you 360 degrees while you're moving.  It will do this if you're relatively stationary, but once you start moving at any speed, that would cause the Mavic to travel backwards.  It won't do that if you have obstacle avoidance enabled, unless you also "enable backward flying" in the visual navigation settings.

I hope this helps.

You will notice once you select an object there are 3 different modes of active track.  Trace, Profile, & spotlight.  I generally have the best luck in profile.  I do notice when using trace I seem to have to regularly verify the speed bar is set to a higher value...  

Trace - aircraft tracks at a constant distance and you can set to orbit the object
Profile - tracks at constant angle and distance
Spotlight - drone does not trace object but will follow it with camera

Hope this helps.  You can check out page 15 I think in the user manual for full descriptions.

LSLMavic Posted at 2017-7-27 14:41
If I understand your question correctly, you want the Mavic to circle around you 360 degrees while you're moving.  It will do this if you're relatively stationary, but once you start moving at any speed, that would cause the Mavic to travel backwards.  It won't do that if you have obstacle avoidance enabled, unless you also "enable backward flying" in the visual navigation settings.

I hope this helps.

I don't want to circle round the boat. In simplistic terms, I just want to follow the boat along the river almost directly above it.  I understand trace mode is the way to go here.

My problem is, in trace mode at a slider setting of 15 m/sec and a locked on target, the Mavic just doesnt move at the expected and required speed to keep up with a relatively slow moving target

MTUFLYER28 Posted at 2017-7-27 19:55
You will notice once you select an object there are 3 different modes of active track.  Trace, Profile, & spotlight.  I generally have the best luck in profile.  I do notice when using trace I seem to have to regularly verify the speed bar is set to a higher value...  

Trace - aircraft tracks at a constant distance and you can set to orbit the object

Profile wouldn't help with my requirement here, I don't think.  I need to fly almost directly above, but slightly behind the boat.  My understanding is that Trace mode would be the way to go.  But would it still keep up anyway in profile mode?

I did some footage from behind my boat and I'm pretty sure I used profile.  Either way it had no real issue keeping up at speeds of around 20-25 mph

Use profile mode ;) The drone will try to keep the initial angle between itself and the subject so if you behind the boat it will stay behind. I've managed speed up to 60kmh (34mph)

My test and video says 25 miles per hour and you can fly a 360 degree angle around  a moving boat.....

Thanks guys.  I'll give profile mode a go and see how it goes.  Watch this space

Well, I think I'm going to have this Active Track sussed.  This afternoon, I set up to follow a car and set the mode to Profile.  The Mavic followed a car travelling at 20 mph very nicely.

Now to put that knowledge to good use on the water
Many thanks to ars.fabula