Tracking boats

How can people in the shore track a ship or a boat in the seas? Can a ship or a boat be tracked without the captain informing their location?

Ships nowadays broadcast their position, course, speed etc. to nearby vessels by a system called AIS. These transmissions can be received within line of sight by shore stations, and by satellites.

Services such as and allow you to see the shore-based information, and for money also the satellite.

The most common way is with AIS which broadcasts position and motion vector periodically over VHF. It was meant as a beaconing system for ships to self-identify to other vessels within line-of-sight. But there have been shore stations set up worldwide that forward their targets to centralized databases; some make them available for free or subscription over the internet.

Then someone figured out that satellites could also pick up the signals and a whole new world of tracking opened. I think recent changes to the standard help the satellite folk.

@dbeierl pointed at two of the services. Beware that coverage isn’t universal.

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If you’re talking corporations or nations there are downward looking radars, underseas microphone networks, over the horizon radars, electronic emissions detectors. My favorite are Earth monitoring satellites that track various greenhouse gasses, heat emissions and even agricultural and traffic monitoring which can also track ships. Together these create multiple layers of observations making the position of all ships known at all times in all weather no matter what the captain or crew do to hide themselves.

The crew can turn the system off although they are not supposed to.

Governments track you through LRITS. Turn off your GMDSS and find out how fast the phone calls start coming in.

Had one malfunction in Trinidad, that was fun!

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I was speaking with an ex-US State Department employee. He was charged with tracking cargoes and ships that violated US sanctions. He would send the government that violated a sanction a photograph of the vessel loading the cargo, the route the vessel took to discharge port and a photograph of the ship discharging the cargo, all time stamped. He explained that these were not low resolution Google Earth type photographs, but rather, high resolution photographs taken with satellites that only the government has access to. He said, the resolution was so fine, he could read the instructions on packing materials. Yes, here in the US, big brother is watching.

Keep in mind it’s easy to transmit false information on AIS if one wanted to.

Nowadays, the vessels are equipped with an AIS transmittal which transmutes the position, course, speed and etc. Sometimes, you can get false data, it happens, but it’s rare.

There are some services providers that help you to see the vessel movement and get more accurate data either terrestrial or Satellite with different prices, like datalastic(good option for affordable data) or marinetraffic(for little bit pricy data)