The Best EPIRB

[jimh]

In September 2016 McMurdo announced a new line of emergency position-indicating radio beacon (EPIRB) devices that combine four different frequency spectrum transmitters and receivers into one housing: the McMurdo SmartFind G8 AIS.

The McMurdo SmartFind G8 AIS is a distress beacon that operate on all four frequency bands employed for search and rescue:

--GNSS receivers at frequencies at L-band, about 1,575-Mhz, to establish a precision position fix;

--radio location beacon transmitter at 406-MHz, for coarse position fixing, alerting of the distress to rescue authorities, and homing;

--radio location beacon transmitter at 121.5-MHz for homing, and

--automatic identification system (AIS) transponder at 162-MHz for localized precision position transmission.

Most EPIRBs transmit on 406-MHz and 121.5-MHz to orbiting satellites or aircraft. This alerts the COSPAS-SARSAT system of the distress situation, and also develops a coarse position solution based on various position finding techniques from analysis of the signal reception by the satellites. With GNSS reception, the new McMurdo SmartFind G8 AIS will also send precision position information as an AIS signal at 162-Mhz. The GNSS receivers are able to receive GPS, GLONASS, and Galileo signals. Responders will be able to obtain precision position location via AIS when in a range of 10-miles or less.

The McMurdo-branded SmartFind G8 AIS is not available for sale at this moment; it awaits the necessary authorization from the FCC in order to be offered for sale in the USA.

The AIS transponder in a McMurdo-branded SmartFind G8 AIS is a type of man overboard automatic identification system (MOB AIS) transponder. A MOB AIS is a small, individualized transponder that would typically be worn by crew members working on deck. A MOB AIS contains a GNSS receiver and AIS transponder. It obtains its position by GNSS reception and then transmits that data via AIS. These MOB AIS transmit their position once per minute.

[jimh]

About the only device not included in the McMurdo SmartFind G8 AIS EPIRB is a DSC-transmitter. Some man-overboard rescue devices also include a DSC transmitter that sends a distress alert message via DSC. This is just a local alerting method, as a DSC signal transmitted from water level on a short antenna is not going very far. Perhaps 10-miles at best would be the range to another ship, but farther to aircraft. On the other hand, sending with DSC means a much higher chance that a boat in range will have a DSC radio; not every boat has an AIS receiver, but just about all boats have DSC radios now. In the USA it has been mandatory that VHF Marine Band radios have DSC features for many years.

Once an DSC radio has been programmed to send a distress alert, it should automatically repeat the distress alert transmission every three to five minutes during the first 30-minutes of activation, then once every 10-minutes after that (until the battery is exhausted, I presume).

[jimh]

The McMurdo SmartFind G8 AIS EPIRB appears to still be awaiting approval from the FCC, and remains unavailable in the USA.