The PLB AIS unit (MOB1) is operating on the 161.975 and 162.025 frequencies.
It transmits a AIS address starting with a "9", which alerts AIS units within the area.
It is a 1 watt transmission
. transmitting seven times a minute.
Range is approximately one mile, although three may be expected.
To maximize the benefit, have the vessel AIS antenna
at minimum ten feet above the water
line of sight minimum efficiencies.
the AIS receiver must be programmed to receive the digit "9" as well as the plotter if location is to be displayed. Units prior to 2015, particularly lower priced models, may not have the updates available.
Reliance on this equipment
should be utilized as part of a bigger MOB system plan. A good number of criteria must be met by the electronic hand offs to make it work
and MANY EXPECTATIONS/APPLICATIONS ARE OVERCONFIDENT of the reliability
At minimum, test the unit via activation to assure it activates your vessel's AIS system.
Additionally, be aware that specifically the MOB1 DSC
function is entirely dependant on the LOCATION it is programmed- I.E. in the US it will only activate the MMSI of the mother vessel, In Canada
it is not a permitted function period, in many other countries it is an all ships DSC call.