Originally Posted by nigel1
Tested an AIS
SART last year. Receiving antenna
about 30m above sea level, and the AIS
SART at sea level. Lost
the signal at 4 miles.
So if you go over the side, and you are single
handing, best hope that another boat with an AIS unit is pretty close.
I'd like to think that with a PLB, in coastal or near coastal waters, if you activated the PLB you would have some chance. MRCC would pick up the signal, make a call to your contact number, confirm you are out on a boat, and hopefully dispatch a SAR helo to go look. That's assuming that the coast state in to who's waters you fell have the assets to do this.
Its worth noting that current
SAR ground station practice is to confirm geostationary SAR alerts ( GEPIRB) by waiting until a doppler flypast has occurred, Hence there can be a significant delay in ground station detection in reality. On top of that you have the delay in contacting listed phone
numbers and determining if a real emergency
has been declared. This is exacerbated by the huge number of false ePIRB
alarms ( > 90%)
Hence in temperate climates, I would contend that PLBs ( which where never really intended for marine
use) are close to useless, in fact I would argue its a dead body location device.
With AIS sarts, the closest vessel you fell off, is the most likely to be the one to recover you. But yes, on a fast merchant ship , 4 miles doesn't give you a lot of time to remain in the detection window.