Okay, so here's the thing, I live near a cruise port and sometimes me and a couple of friends go fly in an open field just by its side. Today one of my friends called me and told me he was getting a compass error in the air. We have flied previously with a cruise docked and had no trouble with any signal interference, but today there is a differente cruise here and someone said that it has a jammer to prevent drones flying near it. Previously, we had been approached to be told that we cannot fly directly above the ship and we should keep a distance, but I had not heard about such implementations.

Any ideas? Is this possible/true?

i dont think a jammer would cause a compass error. it must be all the metal and magnets from the ships.

Not likely.  The signal to jam the P3 is the same sign as the Wifi on the ship.  They would be effing up the whole ship to prevent your flying.  I do not see this happening.

Signal jamming is illegal virtually everywhere, and a cruise ship would not be equipped with such a device, particularly for simply discouraging drone users. As also said by Michael, jamming has no effect on the compass system anyway. It is more likely that you were experiencing 'flooding' of the radio spectrum with WiFi systems on board the ship.

Einsteins?  Nah, just just friendly folks offering a possible perspective to the discussion.  For the benefit of the less enlightened let me point out the original poster asked:  "Any ideas? Is this possible/true?"

I have flown near a few ships and have found even in line of site to my r/c all of a sudden when getting close I got a weak transmission signal so I would assume it's alot of R/F noise given off by the ship.

Hi ,carlo
It could be the metal ship that caused the compass error . Please keep distance from that kind of thing in case of crash .

The radar system within the radome was probably also emitting a fairly strong signal. The 2.4 gHZ system used for the wifi within the ship wouldn't be effected due to the number of repeaters inside the ship.

The RF given off by the radar was the probable cause for your compass error.

I imagine that enormous chunk of metal that is the ship would have an affect on the compass.

Pebble beach Golf course in Monterey, CA has a drone jamming system. I was trying to figure out they could legally do it, and i think they just run yagi antenna's pointing offshore on all 2.4 ghz wifi channels with their network! that way it is directional and doesn't disturb there neighbors but keeps people from flying in from over the ocean ( like the guy who buzzed the greens in the US Open last year!) If they broadcast on all frequencies they could easily build this system for less than a thousand dollars it would just take a rack of wifi routers and one pole with the antennas!

Compass errors wouldn't be a jammer though, when you try to fly offshore near Pebble beach you will have full signal, then as soon as you hit the edge of their property (even if you are 500 meters offshore) all signal, video and RC goes from %100 to zero in about five feet!

plumbob11 Posted at 2015-11-26 23:30
Pebble beach Golf course in Monterey, CA has a drone jamming system. I was trying to figure out they ...

Legally they can't jam the frequency. If you play the course and find a very high WIFI signal, I'd be tempted to make a report with the FCC and make them do their job.

I have an hexacopter that uses 900 the mHZ frequency, so I could still fly over the course. Unless there is a legal non fly zone set up, they can pound sand.

The course can submit a petition to the FAA to have a special exemption put into place closing the airspace for the tournament, If they were to go for a full time restriction, that might be a problem for all involved.

A big active radar creates alot if interference. That might have been the case.