When the weather is beautiful, flying a drone over water is the perfect chance to get that picturesque video
shot. But some easy pro tips keep your drone safe if you’re flying it within water-based locations. Here are 6
great tips that every drone enthusiast should follow.
Vision Position Sensors (VPS)
Here’s a highly-debated topic that deserves its’ own detailed review, whether or not these should be
activated or not. This sensor is focused at a 40-degree angle using an ultra-sonic and visual aids to maintain
stability. It uses defined patterns to help stabilize your drone level. Many of the older user Go-app guides
used-to inform operators to disable the VPS over water. This reasoning was given so your drone would autocorrect its’ position and climb suddenly. But this is not the case with newer drone models that have these
two sensors. Here’s why:
• Moving Water Vs Prop Wash
As a drone moves over water at an average height of 20 feet (over 7 meters), your VPS stands a better
chance at recognizing visual landmarks. These can include the edge of the shore-line, beaches, and solid
ground. It allows a steady flight that won’t get confused with moving bodies of water so easily. But what
happens when you fly your drone with the VPS on if you’re over open water at low altitudes?
This is when a phenomenon called prop wash’ can affect these sensors. The prop wash disturbs these ultrasonic sensors when your drone is around 3-4 feet above the water. The downward rotor airflow causes the
surface of the water to radiate outward. Rather than climbing higher to avoid hitting the water, the ultrasonic sensor causes your drone to drop lower. The 40-degree sensor circumference then gets further
It’s been hypothesized that downward visual position sensors are blocked by the water, as it reads height
through ultra-sound emissions. Other operators are blaming satellite and GPS connectivity. By turning-off
the VPS of both of the downward sensors, you can still maintain VLOS altitude without fighting your drone.
This helps to reduce the automatic dipping effect if you are simply hovering. When moving in a direct path,
this problem is eliminated altogether.
It’s never advised to go fly your drone on a windy day, no matter how experienced you are. The problem
with wind currents is that they can change suddenly due to hot or cold weather conditions. Another problem
is that you cannot see how wind currents are moving and can be unpredictable just like ocean rip-tides.
Thankfully, many of the newer Go-apps such as UAV Forecast or Hover are free to download. These give
instant weather conditions, wind strength, and even ideal altitude for the UAV flight.
They also provide helpful information on electromagnetic disturbances that can affect your drone’s GPS
signals. Both apps are essential to have and always user-friendly. Anytime you decide to go flying, double check the weather reports first before making a bad decision.
Sunlight Glare and Water Reflection
Another subject that is seldom mentioned when flying a drone over water is the problem with sunlight and
light reflection. Water is an amazing liquid that does appear to be invisible at certain times. It can also be a
highly-reflective surface that bounces light naturally. Your drone most-likely comes with a second visual aid
called a DJI vision sensor. This helps your drone sense obstacles and terrain through real-time visual
mapping. But it has one vital flaw and that is water glare that blinds this sensor instantly.
You might like sending out your drone at certain times of the day to the lake or Oceanside. When it comes to
a spectacular sunrise or sunset, water will light up due to the angle of the sun. When it does, your drone is
flying blind and likely not able to give a reasonable anti-collision response if you are near trees or cliff-sides.
This is another reason why your VPS should be switched-off while flying over water.
• ND filters
It’s worth a fair mention to include that any onboard camera used for video also has additional ND filters.
This helps with sunlight and glare. It’s not clear whether neutral density or polarizing filters can be used for
the vision sensor underneath your drone? It would make a lot of sense to reduce glare issues by covering this
sensor since it uses visual imagery. Yet perhaps this is an issue that has not been fully tested yet.
Beware of the Birds
Let’s be honest about the problem with birds. They are curious creatures that can be a threat to your drone.
Seagulls are notorious for getting too close to your hovering craft. The sound will attract them and it’s best to
get your drone higher ground very quickly. This is especially important when your drone is right over open
water. In fact, avoid all birds if they are present around your location. You don’t want to face fines or
charges of animal cruelty if they decided to attack your drone.
This also goes for isolated locations at lakes and rivers where overprotective Mommy’ birds are nesting.
Hawks, ravens, eagles, and even bats are known to be attracted to your drone. Just so you know the fine for
killing or injuring an American Bald Eagle can be high! As much as 10,000 US dollars and possible prison
time, if you get caught buzzing their nest. All operators must stay clear of an eagle nest by 1000 feet away.
In general, this should apply to all types of birds for the very same reasoning.
Visual Line of Sight (VLOS)
You should always maintain a good visual line of sight when your UAV is over the water. This means you
need to position yourself where the light allows you to keep a careful eye on its’ location. Any decent drone
will have additional software installed that gives you a range that can be controlled. You need to set a limit
on how far your fly no matter what your onboard cameras can see.
• Set your home point
For most of you who might not know there is something called DJI. It was created by Frank Wang and he
developed Da Jiang Innovations and became what is the hobby drone for all flight enthusiasts. This was an
added innovation that was built-into a drone so battery levels and near-collisions were avoided. This
automatic feature has extended into adding a distance control or if your drone goes out of range. It’s also a
failsafe feature that can keep your drone from flying off into the sunset.
Most operators will set their home point before take-off so your drone knows where to return to. Learning to
set that home point will save you a lot of money in the long run. If your drone is flashing low battery over
the water, or you lose GPS service, this feature is a must.
Beware of GPS towers
Having plenty of GPS for your drone is great for getting a better position on where your craft is located.
Unfortunately for GPS towers, their powerful signal can also work against you. It can interfere with the
drone’s navigation and your drone may end-up lost in the water. This is another reason why the home point
feature should always be set-up before you fly. The newer towers are using stronger signals than ever before.
Some of these towers are now already equipped with 5G technology.
Save yourself the extra hassle and avoid areas that have GPS towers when flying a drone over water.
Magnetic interference is the main reason for drone failure. Your compass calibration is also something that
will be a counter-measure in case of heavy GPS interference. This is for the same reason that you would
need to shut-off GPS mode flying between tall buildings. So if you are flying near known GPS towers, you
might want to consider switching-off your GPS Mode and enable the Home Point setting