So, you’ve mastered flying over vast fields and forests and are just itching to take your Spark over the water and get those shots that really seem to impress, well, you’ve come to the right place.
You’ll be glad to know that flying your little drone over the water isn’t as daunting as it sounds, in this article I’ll cover everything you need to know about preparing for, and carrying out, a safe flight over water.
The main areas to consider when flying over water are as follows:
- GPS / Vision System
- Environmental Conditions
- RTH (Return to Home)
- Optional Accessories
It kind of goes without saying, but the first step should be to ensure that your Spark is updated, calibrated and all batteries / controllers are fully charged before you commence flying anyway . . . but this is especially important when preparing to fly over a lake or the sea as your emergency landing options are greatly reduced whilst you are over the ‘wet stuff’.
GPS / Vision System
Secondly, I do not recommend flying over water unless you have confirmed that you have a GPS lock AND you are not receiving any compass warnings / notifications.
If you were to sit and read the 56 page manual of the DJI Spark you would come across the following cautionary notice with regards to the ‘Vision System’:
3D Sensing and Vision System performance are affected by the type of surface being flown over. The aircraft will switch from P Mode to ATTI Mode automatically if neither GPS or Vision System are available. Please be vigilant when operating Spark in the following situations:
- Flying over highly reflective surfaces
- Flying over water or transparent surfaces
- Flying over surfaces without clear patterns of texture
They mention several other factors, but the above all relate (in my opinion) to flying over water. So, what’s all the fuss about?
9 times out of 10 (hopefully) you will be flying your drone in P (Positioning) Mode which means your Spark is either relying on GPS and / or the Vision System to stabilise itself.
Let’s say for arguments sake you lose your GPS lock whilst flying over water . . . now you are reliant on just the Vision System to keep you stable and away from the much ‘feared’ ATTI mode.
The Vision System uses both 3D infrared and a downward facing camera to help stabilise your Spark at low altitude, both of which can get hugely confused whilst flying over water.
The 3D infrared module can penetrate through the water and believe it’s higher than it actually is . . . basically it sees the ‘bed’ as the base point rather than the water . . . which has been known to cause the Spark to change altitude and lower itself . . . splashdown!
Flowing water can also confuse the Vision System further by inviting the Spark to ‘lock on’ to a moving texture . . . which, once again, can cause the Spark to drift.
And finally, there is the ever-changing reflective light issue. Waves will reflect light and may create the illusion of gaining or losing altitude, causing the Spark to potentially dunk into the water also.
So, as you can see, the Vision System is an area that you should understand before you fly over bodies of water.
What’s my solution? Controversial I appreciate, but if I was to lose GPS lock I would rather fly in ATTI mode than rely on the Vision System when flying over water . . . therefore I always ensure I am flying at least 8m above the surface to prevent the Vision System influencing my flight.
This is an easy one to cover . . . when preparing to fly over water play closer attention to the general weather forecast. I recommend using the ‘UAV Forecast’ app . . . if it’s blowing gusts of over 20 mph at a low altitude . . . come back and try again later I would say.
RTH (Return to Home)
If you are launching over water (E.G from a boat), do NOT rely on the Home Point for returning to home as your boat may drift from the original home point location.
It’s still important to ensure the Home Point is set (as it will hopefully be close), but it will be necessary for you to take over manually and be in control of the final landing phase to ensure you land safely.
Also, don’t be under the false impression that if you stand close to your Spark on the edge of the water and simply fly around a couple of metres out to get the photo / video you are looking for, that you are safe . . . many forget that the RTH process when the Spark is 3m away is to descend directly down . . . splash!
Although I haven’t personally tried these yet, it is possible to get float kits for the Spark which allow you to take off / land from water.
If you are interested, here is a link to one I’ve found on Amazon:
Personally I wouldn’t see offerings like this as an invitation to treat water as a safe landing platform, but it may help retrieve drones if the worst was to happen and you do ‘crash’ in the water. If you have purchased DJI Care Refresh then many have reported they have been unable to ‘claim’ if they don’t have a drone to return.
And that’s your lot! Hopefully this article gives you a degree of confidence when flying over water.
Be careful, follow the guidance and you SHOULD have no problems getting those shots you are looking for and impressing your friends and family!