Marine Vessel tracking device
 

Have read in one of the threads regarding over water ferry flights there is a devise that ships have that automatically transmits their position. There is another unit that a pilot can fit to his aircraft so he can see any ships that are within 100 nm of his position.

Anyone know what it is?

The device you need is an AIS receiver. Like aircraft, ships are also equipped with transponders, which broadcast ship's position, name and other information.

Its called AIS, you can use the following web site to track live traffic


ShipAIS

One of these might be of interest to you.

I know nothing of either, and have no experience of either...so can't make any recomondations.

Spot Tracker

Spider Tracks Aircraft Tracking

That would be a great piece of equipment for Atlantic crossings

AIS vs. Transponder
 

Anton, pretty sure you're correct about the "broadcast" comment, but not the "transponder" as we're accustomed to in airplanes - i.e., ship AIS transmits at random, not in response to an interrogation.

An AIS receiver remains a passive device. (If anyone knows more, please pipe in :)).

Cheers,

Trolltuner

No it is passive. Transmits the GPS position and message every few seconds. In range of the coast, and coast staions pick it up. In range of another ship it is received directly.

The Coastguard SAR choppers have them fitted so the coastguard can track the helo.....they only cost a few £00.....

About the tracking service
 

You can check this out Marine Traffic Vessel Tracking | Free AIS tracking I think it will help you :D