The P-3 Orion was specifically designed to detect submarines. We designed and installed some of the COMSEC electronics for the P-3, and a lot that cannot be talked about in open forums or private conversations for that matter. The US security agreements we signed are still in force.
So I used a term that most would likely understand, sonar, many used that characterization inside the designers world as well, it hid somewhat what was really going on to the lay person, lazy and easy ... Sorry for joining the lazy crowd ... What's a magnetic anomaly detector — Well its sort of like a sonar for subs. OK I get it. The long MAD boom is the characteristic feature of the P-3 Orion sub hunter.
There are far better aircraft and instrument packages to do what the Bluto of Venezuela was talking about than is carried by the now mostly obsolete P-3s. Today I think the only thing they do is drug interdiction patrol, but even then their equipment is highly dated. Their last upgrade was about 10 years ago, and the P-3 airframe is basically a Lockheed Electra 188 last built in I think the 1960s. Today Moffett Field is used to house google millionaires personal airplanes ... LOL. The thousands that were employed there to hunt subs has been laid off. I think that Moffett Naval Air Station has been decommissioned and turned over to NASA a while back, or something like that.
Above is one of the original freight converted Electra's. I seriously doubt a P-3 was what was allegedly spotted, if anything.
But back to the original article intent, it's nothing more than a distraction being used by Bluto to try and take the people off their real problem, they are slowly starving.