Tips for Flying a Drone Over Water (Video)
As we are currently in spring and with summer quickly approaching, people are enjoying more and more water-based activities. Some of these activities will be filmed by drone.
A question that generally arises around this time of year, after the lakes and ponds have unfrozen and folks get back to the waterways is: What steps are needed to fly a drone safely and confidently around and above water, and ensure it returns home?
In this article and the included YouTube video, we will go over various tips and steps needed to fly any drone over water safely, as well as some weather-related considerations to aid in this. We’ll be using DJI drones for the step-by-step portions of this article.
1. Plan, Plan, Plan
Plan or know your environment. This is a simple statement, but very loaded.
One of the great things about many modern drones is their size and portability. Because of this, we can easily toss a foldable drone in a bag or in a vehicle and fly when near an interesting location.
If we are in a location we know like the back of our hand, flying that area’s waterways should be no big issue.
Knowing the area, however, means:
- knowing the environment’s inhabitants such as birds and other wildlife that can pose a threat to your drone
- knowing if there are actual no-fly zones that intersect the water
- knowing if there are seaplanes or helicopters in the vicinity
- knowing if there are drone no-fly zones posted by the local government
If you are planning an actual trip to a specific, previously unknown area, like somewhere on vacation, then it is recommended to plan the flight.
Planning your flight can be done in the following ways:
Consult Google Maps or Apple Maps
This is an easy first step, as it basically only requires putting in an address, or an address in the vicinity of your travel destination, putting the map in hybrid view (to see the streets, landscape, and topography), and then scrolling around the map at a magnification that works for your view.
Research Using Drone-Specific Apps
After getting a lay of the land with Google or Apple Maps, using a drone-specific app can help dive deeper and see what types of airspace and warnings are in the vicinity.
Apps that can aid in this, that we recommend are:
- UA Forcast
» MORE: 13 Apps Every Drone Pilot Needs (Must Read)
» MORE: How to Apply for LAANC on a Smart Device using ALOFT Air Control (Video)
All of the apps mentioned here give much-needed information for drone flights such as real-time maps, active airspace, with Aloft and UA Forcast displaying weather-related information.
2. Pre-Flight Checks
Something recommended by most drone operators, regardless of where flying, is preflight checks.
Why is this so important? Because unlike flying over land, the chances of retrieving a submerged drone might be very small, whereas a crashed drone, on land, can more easily be recovered, with minimal damage.
Some of the major areas to check, before flying are:
- Batteries. Drone and Remote Controller
- GPS Satellite lock
- Return to home. We will touch on this more
While these areas are important to check prior to flight, there are of course many more areas that should be built-in to the pre-flight process prior to any flight, all of which can save your drone from “drowning” or crashing into a person or property.
» MORE: What to Check Your Drone for Before a Flight (Read This First)
3. Turn off Vision Positioning Systems (VPS) in DJI Go 4
Now this is an interesting tip, one that even DJI recommends.
Note: This step is only for those using the older DJI Go 4 app to fly their drones. The newer DJI Fly app and the drones associated with it (DJI Air 2 and 2S, Mini 2, 3, and 3 Pro, as well as the Mavic 3 series) cannot turn off the VPS system.
In short, VPS is a technology used by DJI drones to map the surrounding surface below the drone, aiding in its positioning. This partially helps keep it steady when there is no stick input.
Because water is a reflective surface, flying over it with VPS on can cause issues, one of which is the drone attempting to land in the water when too close to the surface.
To disable the Vision Positioning System (VPS) in DJI drones running DJI Go 4:
STEP 1: Go into the Go 4 menu system by tapping the 3 dots in the upper right-hand corner of the screen.
STEP 2: Locate and enter the sensor(s) tab on the left-hand side of the screen.
STEP 3: Ensure Obstacle Avoidance is enabled.
STEP 4: Go into Advanced Settings.
STEP 5: Turn off “Enable Vision Positioning.
4. Manually Update Home Point
This tip is more for those that will be filming over the water from a boat, kayak, or other type of watercraft.
When on a moving boat, it is important to update the home point regularly, as the drone operator might be in multiple locations during the time of the flight. In the case of an RTH (return to home) incident, it is beneficial for the drone to return to the current location
Those that plan to film waterways and will be walking the length of the shore might also benefit from updating the home point regularly, as one could easily be quite a distance from the initial launch site.
For filming waterways, you can either:
- Manually set the home point
- Set the home point to follow the remote controller. This is best for when on a boat.
To update the home point in the DJI Fly app:
STEP 1: After going into the general settings, under the Safety tab go into Update Home Point.
You will then be brought to the adjust home point map.
STEP 2: Drag the map around until the H (home point) has been moved to where you’d currently like it.
If you would like to set the remote controller as your home point, simply press the RC icon and the home point will be set to the controller.
5. Know the Weather and Conditions
Another very important thing to know or research when flying over water is what the weather is going to be like. In particular, knowing the wind and wind gust speed.
Sure you can look around and see pretty clearly if it is going to rain, however, knowing what the wind is doing a few hundred feet above the water can mean the difference between a successful flight or a downed or lost drone.
When it comes to wind, although it might be constant at 3 or 4 mph a few dozen feet from the ground, once at 100 or 200 feet in height, that breeze can suddenly turn into raging gusts, making it difficult to control the drone or even return the drone to your current position.
Also, wind speed can quickly deplete a drone battery, causing other types of issues (mentioned later).
Another thing to consider is something called convective currents.
Convective currents are affected by objects that hold or generate either heat or cold. Depending on the source affecting them will determine how your drone will fly through the current.
For instance, if flying on a summer day and a drone takes off from a hot parking lot, the air currents push the drone upwards (hot air rises). Once that drone begins to cross a cooler area during flight, say a body of water, the currents will push down on the drone (cool air falls).
Being aware of these currents can aid in keeping a drone out of the water if flying too low. In these situations, the drone operator can be prepared for the adverse action of the current when flying over cool water in the summer, and adjust accordingly.
6. Be Mindful of Obstacles
When flying around and over waterways, there are obstacles to be aware of that one might not normally encounter when flying over land.
Waves and Seaspray
Being aware of waves and seaspray really affects those daring drone operators that aim to get right in on the action with their shots.
An unsuspecting wave can and has taken out the drones of those that are paying more attention to the shot rather than their surroundings.
Seaspray is also an enemy of drones. Although it might not cause a drone to immediately fall from the sky, there could be damaging effects to the drone over time as the internals of the drone begins to corrode from exposure to salt water.
When filming boats, it is advisable to keep a reasonable distance. As the saying goes “objects in mirror are closer than they appear”. Likewise, a boat, while filming, may seem a lot further away than it really is either to the naked eye, from a distance, or on a tiny smart device screen.
I have personally seen drones crash into boats while filming. Again, this is mostly because of not paying attention to the immediate filming area or misjudging the boat’s path.
Living and filming in a state where predatory birds are quite common, it is a must to look out for these and plan accordingly when filming in their vicinity.
This is a touchy subject for me, as I have been the unfortunate recipient of an osprey strike that drowned one of our drones. Thankfully I was able to go swimming and retrieve it.
A good tip when flying near water is to bring the drone up a few dozen feet above where it launched and wait a few seconds to see if any birds show interest in it. If none do, then you are good to fly.
If any birds do try to engage the drone, fly straight up to avoid them, as birds cannot fly straight up. After doing this a few times, the birds most likely will lose interest, if not near their nest.
If flying in the vicinity of a nesting bird, it is best to fly away from the immediate area.
If you live in Alabama, Florida, Georgia, Louisiana, or Texas (just to name a few), being cautious of alligators is recommended.
Alligators can launch themselves from the water to a height of 5 feet. This is something they commonly do to grab birds and rodents off low-lying limbs and branches over the water. They can do the same to low-flying drones.
There has been at least one recently documented news incident of an alligator grabbing a drone out of the sky and then the drone caught fire as the alligator chewed on it, no doubt causing some harm to the alligator.
There’s a mentality Floridians have and that is, if there’s water, assume there’s a gator in it. This type of thinking could one day save a drone if flying in the mentioned states.
7. Avoid Running Batteries Down Completely
This might sound like a no-brainer, however, when in the middle of flying, one can quickly lose a sense of time and be utterly shocked when the drone begins to initiate RTH (return to home) due to a lack of battery percentage.
The reason it is best to avoid running batteries down completely is based on something mentioned early, that being wind.
When flying along seashores, over open water, and low-lying lakes, the wind can kick up literally out of nowhere. If the drone is out a few hundred yards, on only a few percent battery life, and the drone is flying against the wind, there is a very strong chance the drone will not make it back home.
Again, this is something that is well documented online, where quite a few people have lost their drones to wind due to not having enough battery percentage to get back to the home point.
We are always suggesting landing around the 25% to 30% mark, for battery health. When it comes to flying around oceans and lakes, this process can prove beneficial.
8. Use Intelligent Flight Modes
This last tip is a matter of preference.
Many newer drones have some sort of intelligent flight mode built in, whether it be some sort of course lock, Point of Interest mode, or follow-me mode.
When flying over water, using something like a course lock or follow-me mode (for boats or jet skis) will enable the operator to either “set a course and forget it” or draw a box around a watercraft, let the drone do its thing, while the pilot focuses on the shot or video and minding things like battery percentage, etc.
» MORE: DJI Mini 3 Pro Intelligent Flight Modes (Explained for Beginners)
Recommended Flying Height
When it comes to flying over water, one thing to keep in mind is the best minimum height to safely fly the drone without losing it to water.
DJI strongly suggests flying no lower than 3 feet (1 meter) above the water’s surface. This is important, as we have touched on, waves can kick up causing the drone to be lost, convective currents can cause the drone to suddenly dip, or the drone may initiate landing procedures thinking the water’s surface is the ground.
When flying on the beach, it is advised to bring along a landing pad, as launching from one minimizes the amount of sand that can be blown into the motors or even the drone’s internals.
If you don’t have a landing pad, in a pinch, I personally have used and recommend using a floormat from inside the car.
Simply place the rubber end of the mat on the sand (if you have mats that also have a carpeted side) and go. This works very well, albeit slightly cumbersome, as mats don’t fold for easy storage in a gear bag.