nimbusgb wrote:
Following a thread on uk.rec.boats about pirates ......

All vessels over 200 tonne are supposed to carry AIS transmitters. Does
anyone know what the regulations are if you *want* to carry AIS being
under 200 tonnes? How does anyone police the use of the system. It
appears to me that there is no registration id of the transmitting
equipment and anyway that could be falsified.

Wrt. identification: AIS transmits ship's name, MMSI number, IMO
registration number and callsign. MMSI number is transmitted in every
message, and functions as the key used to correlate messages coming from
the same transmitter. The other fields are not mandatory.

And yes, all of these fields can be falsified. You could also state
false statements about depth, length, etc. easily, as these are also
just entered into the AIS transmitter's configuration. Transmitting a
false GPS position, speed and course would also be possible, but would
require more work.

Anyone with a DSC radio will (should) have a MMSI number. Anyone with a
radio license will have a call sign. Only the IMO number will remain
blank for non-IMO classified ships.

--
Kees