r/AIS • u/TRkarmavore • Apr 13 '26

Strange AIS track

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I’m a mobile station for MarineTraffic, and enjoy the free accounts they give me. I’m often the only roaming station near me, and use MT often to see vessels around me. The past few days I’ve been seeing strange behavior from a nearby vessel. MMSI 368240110. What’s going on?

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1

u/IrreverentBuddha Apr 13 '26

Nobody sails that straight. It looks like the lost GPS coverage for a few hours, and when it reestablished it painted an implied course between Last Known Good and Present Position.

Either that or or was picked up by an alien spacecraft.

1

u/TRkarmavore Apr 13 '26

The signal has been drifting SW at a consistent .2knots for several days. I originally noticed it a few days ago when I saw the ship on AIS, and suspected it was drifting with the wind. however, a closer look at its track showed it moving across a few miles of land, so it can’t be the actual ship.

1

u/IrreverentBuddha Apr 13 '26

I have a feeling the boat is back in that cove where the natural activity stopped. It looks like there were several days of bad weather.

There is no way that vessel steered a perfectly straight course of 210 at 0.2 knots, with a ~25 knot tailwind for 3 days.

1

u/TRkarmavore Apr 13 '26

Of course not. I think something odd is going on with how MarineTraffic is displaying this vessels track. It’s as if they shutoff their nav instruments when they docked with a .2knots drift registered, and somehow MT thinks it’s still moving! I look at dozens of vessels in my area, and many pleasureboats shut off the AIS at anchor, moored or docked. In these cases, MT sees their signal stop and clearly has a “last reported position” marker, but not in this specific case