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1987 Liberty 38
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Discussion Starter · #1 ·
Water Boat Watercraft Naval architecture Vehicle

I lost a second drone last week.

I've been flying and building RC planes, helicopters and drones for many years.

I crashed a DJI Mavic Air 2S last year into the headsail and it hit the deck and then bounced into deep water.

I had fly-away insurance. DJI said there was no indication that the drone did not follow instructions and didn't cover the loss. It flew to the boat, stopped and then just got a mind of its own and flew in a crazy pattern and then zoomed forward into the sail and crashed.

I waited almost a year and decided to buy another DJI Mavic Air 2S. It arrived a month or so ago and I tested it in Stuart, FL at the marina and it was great. Everything worked.

I launched it in the Atlantic last week in light winds and 2.5k SOG and took 15 minutes of video and photos. I was sitting in the chair behind the wheel. At one point I noticed my B&G MTD was not displaying any wind information. I didn't think anything about it except that it was odd there was no wind info since that always had worked before. A minute or so later it came on and everything was back to normal.

I stood and walked to the port lifeline gate next to the cockpit and brought the drone in to catch it like I always do. It flew to me fine. About 15 feet from the boat it stopped. Things started to get weird and if I pushed left it would go up, down, it would go another direction. Finally I turned off all of the safety settings, put it in Sport mode and flew it back a little and it started working fine. I brought it back towards me and at that same point about 2 feet higher than my head and about 15 feet from the boat it stopped coming towards me and turned and flew across the stern of the boat and hit the radar post and flopped into the water.

I just sat down on the cockpit coming and just happened to glance at the B&G chartplotter. The wind was not showing and then almost instantly it came back on.

I have no proof of the connection, but the evidence points to the B&G wireless wind signal crossing with the DJI signal and causing the problems. The receiver for the B&G is on the port side, just aft of where I was trying to land. I would have been standing in a direct path between it and the top of the mast. This has never happened when I was landing on the foredeck or on the starboard side.

Anyway, take that for what it is and if you have a B&G wireless wind receiver on deck and you fly a DJI drone, I'd suggest landing the drone on the other side of the boat or as far away from the receiver as you can get or just turn off the wind instruments for a while during your flight.
 

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‘77 Pearson 10m
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Sorry to hear about your lost drone(s). My DJI Mini 2 and the Mavic 2 operate on either 2.4 or 5.8 GHz and is selectable. I don’t know if the B&G wireless wind operates in either of these bands, but if it does, select the other one for the drone. I would test this theory at the dock to see if you could a) reproduce the problem and b) resolve it with this change.
Good luck.
 

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‘77 Pearson 10m
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I'm not claiming in any way that you're wrong, but if you're right, someone's (B&G or DJI) is probably violating FCC rules, or has managed to spectacularly mess up their wireless implementation.
I know that every time I start using a wireless device, I have to slog through the disclaimer about accepting unwanted interference with other wireless or communication devices. If B&G operates on 2.4 GHz only, it would suggest trying the drone on 5.8 GHz would be a good first step. I doubt there is anything you can do about shifting the B&G band to some other part of the 2.4 band.
 

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Discussion Starter · #8 ·
Sorry to hear about your lost drone(s). My DJI Mini 2 and the Mavic 2 operate on either 2.4 or 5.8 GHz and is selectable. I don’t know if the B&G wireless wind operates in either of these bands, but if it does, select the other one for the drone. I would test this theory at the dock to see if you could a) reproduce the problem and b) resolve it with this change.
Good luck.
I did not know that. I will check next time for drone #3.
 

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Discussion Starter · #10 ·
I know that every time I start using a wireless device, I have to slog through the disclaimer about accepting unwanted interference with other wireless or communication devices. If B&G operates on 2.4 GHz only, it would suggest trying the drone on 5.8 GHz would be a good first step. I doubt there is anything you can do about shifting the B&G band to some other part of the 2.4 band.
If I buy another one from DJI I’ll do that. I have the smart controller already so most likely I’ll give it another go.
 

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Another feature in the Go Fly app, and probably somewhere in other brand’s controller app, is an interference detector that allows you to see high interference bands and set your transmission band to avoid them. This would confirm other interference too
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I'm not claiming in any way that you're wrong, but if you're right, someone's (B&G or DJI) is probably violating FCC rules, or has managed to spectacularly mess up their wireless implementation.
In the US, Wi-fi and bluetooth are subject to Part 15 FCC rules. Part 15 devices have to accept interference from others, but not intentionally interfere with others. Though, one would think that as the drone gets closer to the control device, the drone signal would swamp out the bluetooth signal. Not familiar with drones, but DJI may use adaptive power control for the wifi signal, reducing transmit levels as the aircraft and controls come into proximity.
 

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I'm not claiming in any way that you're wrong, but if you're right, someone's (B&G or DJI) is probably violating FCC rules, or has managed to spectacularly mess up their wireless implementation.
The 2.4 GHz and 5 GHz bands are open. Everyone and anything is allowed to use them, so long as they don't exceed a certain broadcast wattage. Avoiding interference is the responsibility of the operator.

These bands were opened because things in the atmosphere (mostly water vapor) rapidly attenuates the signal. That makes them not very useful for long-range communications, but almost ideal for short-range open broadcasts (e.g. your WiFi router does not interfere with your neighbor's WiFi router because of signal attenuation). The 2.4 GHz band in particular surrounds the 2.45 GHz frequency used by microwave ovens, where the signal attenuation by water is so great that it can be used to heat food (and why older WiFi would go out whenever someone used the microwave, and can still cause problems for bluetooth and wireless mice/keyboards).

Same goes for the new open 60 GHz band (signal absorbed by atmospheric oxygen, used by the somewhat rare 802.11ad for high-speed wireless over a few meters). The older 600 and 900 MHz open bands (mostly used for analog signals like walkie talkies and wireless microphones) are also under the same guidelines. You're not allowed to exceed a certain broadcast strength, and avoiding interference below that is the responsibility of the operator.

There are various cell phone apps which will let you scan for nearby 2.4 GHz and 5 GHz signals. Though they may only show you WLAN channels being used, not RF use per se (e.g. you might not see interference from 2.4 GHz bluetooth connections). If you're aboard a boat at sea, it's almost guaranteed that any interference is being caused by something else aboard your boat. If you're gonna operate expensive equipment which relies on a wireless signal (like a drone), it's probably worth paying for/puting in the extra labor to run wires to connect things like a wind sensor.
 

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Relaying my current experience with the “DJI Refresh” service. Basically it’s an insurance plan with a $49 premium (at least for the Mini 2), 1 year of coverage for 2 damage claims including 1 “Flyaway” claim. The deductible for Flyaway is $225 and damage only claim is $49 for 1st and $59 for the 2nd claim.
I just put in my claim for “flyaway” and am awaiting the quote for coverage replacement. The harsh reality of this is when I got the data analysis report on the flight. It showed all the facts as I recall them, launching from a moving platform, which they call “improper flight environment “and the recommendation not to take off from an unstable platform. The rest of the flight parameters showed what I remember, a painfully short flight right onto the foredeck and collision with the standing rigging before bouncing off the deck and through my desperate hands and into the Chesapeake to be with what must be hundreds of other drones.

Bottom line is they are covering the loss even though this qualifies as a user flight control error (PICNIC-Problem In Captain Not In Computer) and not a drone malfunction or interference.
 

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I’m wondering about buying a drone, so I can take pictures of my boat in full sail. This thread is very interesting, but if the experts still lose their expensive drones through technicalities, what chance do novices like me have?
The question is: What would be a good drone to buy, (hopefully cheap to start with), and the best way to learn, before the big flight.
 

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Not claiming to be an expert, I'm just unfortunate enough to have already learned some hard lessons early. I just recommend practice a LOT, slowly integrating more complex aspects of flying off a boat and shooting videos.
As for which drones to buy, starting relatively cheap makes sense, but cheaper sometimes means fewer features that can keep you out of trouble. Collision avoidance is a mid level feature, although it may not prevent crashing into rigging but may prevent running into sails or the water. Insurance is also a good idea, one that will replace a drone lost in the water, but it's kinda pricey, deductible wise.

Despite my losses, i'm still a huge fan of what drone photography offers sailors.
 

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Not to beat a dead horse, but the DJI FAQs page for the mini notes:

“Additionally, 2.4/5.8 GHz wireless devices can cause interference to the signal. Please avoid high-density Wi-Fi signal sources, and consider turning off the Bluetooth on your mobile devices, as well as idle Bluetooth devices.”

…I’ve been mulling buying a small UAS like one of these for a while so figured I’d do some web window shopping…
 
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