Boat launch can be nerve wrecking. And, if you do it wrong, they may cost you the drone. While the saying that practice makes perfect is completely true here as well, there are number of settings, actions and skills that will help to reduce risk even in the initial phase of getting to grips with the boat launches.
1) RTH procedure – dynamic home point
This is one of the most critical settings for boat launches. In the settings of the RC, you will see screen that looks similar to the below. There should be an option to update the home point. Not all drones and not all apps support this feature, but without it flying from boat is a lot more risky.
If you cannot see this, there might still be an option to update home point manually while you are in flight by dragging the home point to required location (where the boat is currently or nearest land). Updating to landing on nearest piece of land is probably safest way to emergency land anyway. Check your app and your drone flying over land and moving before you attempt this on boat. Whatever you do, make sure that you do NOT use the “Land” option as emergency. Your drone will auto land at 10% anyway, there is no need to make it land sooner.
2) Geofencing – not this time
Geofencing or distance lock is often a good idea, but not when you are flying from a boat. The reason for that is that when the geofence is reached, the drone begins to hover and does not respond to commands until the it is back in the geofenced area. With boat moving, it might take a while to get it back into geofence area. Drone will respond to RTH command – another reason to send this correctly.
3) Hand launch and hand land
Invest some time in practicing hand launching and hand catching the drone. Easiest drones to hand catch are any of Phantom series as you can easily grab it by the landing skids.
The Mavics are a bit more difficult to catch because they have nothing to grab onto, but since they are small, they are probably safer to practice on. You will need to disable the bottom sensors (if your drone has them) as they will not perceive the hand as “suitable to land on” and will attempt to move away.
This may in turn cause the drone to crash into the boat. Bottom sensors should be disabled when flying over water in any case as the reflection may disorientate the drone and cause positioning errors.
4) Allow for boat drift
Unless your boat is anchored it will be moving or drifting. Even when it’s anchored, some movement is likely. You have to be aware of the direction of that movement and carefully chose the position to launch the drone. If the boat is drifting or moving back, launch from the front. If it’s moving forward, launch from the back.
The boat drift may cause the drone appear to be acting erratically and uncontrollable. In fact – this is not the case. The drone is holding the GPS position and it’s the boat movement that is making it appear like it’s moving. If you have ATTI enabled drone, you may want to use ATTI mode to take off altogether and only then switch to GPS.
Make sure you have space and make sure the props are spinning and you feel the drone taking off before you release it. Release the drone slowly while pushing the left stick up to gain some height.
5) Keep the drone in sight
Flying within Visual Line of Sight (VLOS) is the legal requirement that is so frequently forgotten. And not without a reason. With DJI claims that their drones can fly 10 km and more, one would think that this is what law allows… Regardless of whether you normally comply or not, keeping the drone in sight while on a boat, can literally keep you out of the water, especially when you start seeing things go wrong.
On my first boat launch, I nearly lost my drone. Boat was moving fast. The drone was tracking the boat. I was watching the screen, not the drone. Then the boat drifted out of sight. To make things worse, I lost RC connection with drone set to hover. it took me a while to regain control, by when I was almost out of battery life. I managed to land my drone on an island and went to retrieve it afterwards. Luckily – there was land nearby that I could get to. Keeping eyes on the drone would have been kinder on my nerves.
Interference is bad news at any stage, but having your RC signal or video feed lost while flying off the boat is particularly risky. Be aware of any radio, cell phone and wifi towers round you. Not only those ones on land, but also those on vessels. If you fly close to port area, the big transport vessels are likely to have their own transmitters than may cause interference (this beside the fact that in most cases you would not be allowed to fly there anyway…). Masts and steel structures can also cause signal loss, so be careful in ports and close to platforms.
7) Watch out for battery life
As you probably noticed by now, launching and landing are two most critical activities when flying from the boat. For that reason, you should give yourself plenty time to land the boat. You may need to adjust and readjust the position few times and you definitely do not want your drone to start the critical battery auto landing routine.
The landing should be initiated at approx. 40-50% of battery life, which means that you should finish whatever maneuvers you are doing and start bringing the drone back probably at around 60%. Of course it depends on whether you can already see the drone and whether you are far or close to the land. Do not push the limits to far, especially if you have not done many boat launches. Things can (and DO!) go wrong right at the end.
8) Land in sight
Unless you are experienced with boat launches, I recommend that you do your boat flying relatively close to some accessible land. You may go even further and set your home location there (you don’t actually have to land your drone there unless it enters the emergency routine). In the reel below, I luckily was close enough to the land when I lost connectivity and map view.
Do not overestimate yourself and your capabilities. Practice on dry land before you attempt the actual boat launch. If things go wrong – DON’T PANIC. Having a spotter always helps. And – watch out for masts, lines and other small and narrow parts of the boat!
Always make sure that your settings are right for the specific flight!