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Emergency Position Indicating Radiobeacon
Types of EPIRBs
Emergency position indicating radiobeacons (EPIRBs), devices which
cost from $200 to about $1500, are designed to save your life if
you get into trouble by alerting rescue authorities and indicating
your location. EPIRB types are described below:
121.5/243 MHZ. Float-free, automatically-activating, detectable
by aircraft and satellite. Coverage is limited. An alert from
this device to a rescue coordination center may be delayed 4 -
6 or more hours. No longer recommended.
121.5/243 MHZ. Manually activated version of Class A.
No longer recommended.
VHF ch15/16. Manually activated, operates on maritime channels
only. Not detectable by satellite. These devices have been phased
out by the FCC and are no longer recognized.
121.5/243 MHZ. Similar to Class B, except it floats, or is an
integral part of a survival craft. No longer recommended.
406/121.5 MHZ. Float-free, automatically activated EPIRB. Detectable
by satellite anywhere in the world. Recognized by GMDSS.
406/121.5 MHZ. Similar to Category I, except is manually activated.
Some models are also water activated.
1646 MHZ. Float-free, automatically activated EPIRB. Detectable
by Inmarsat geostationary satellite. Recognized by GMDSS. Currently
not sold in the U.S.; however, the Federal Communications Commission
is considering recognizing these devices.
121.5/243 MHz EPIRBs
These are the most common and least expensive type of EPIRB, designed
to be detected by overflying commercial or military aircraft. Satellites
were designed to detect these EPIRBs, but are limited for the following
Satellite detection range is limited for these EPIRBs (satellites
must be within line of sight of both the EPIRB and a ground terminal
for detection to occur),
Frequency congestion in the band used by these devices cause
a high satellite false alert rate (99.8%); consequently, confirmation
is required before search and rescue forces can be deployed,
EPIRBs manufactured before October 1989 may have design or construction
problems (e.g. some models will leak and cease operating when
immersed in water), or may not be detectable by satellite. Such
EPIRBs may no longer be sold,
Because of location ambiguities and frequency congestion in
this band, two or more satellite passes are necessary to determine
if the signal is from an EPIRB and to determine the location of
the EPIRB, delaying rescue by an average of 4 to 6 hours. In some
cases, a rescue can be delayed as long as 12 hours.
One November 3, 2000, the National Oceanic and Atmospheric Administration
(NOAA) announced that satellite processing 121.5/243 MHz emergency
beacons will be terminated on February 1, 2009. Class A and
B EPIRBs must be phased out by that date. The U.S. Coast Guard
no longer recommends these EPIRBs be purchased. See the U.S.
Coast Guard Media Advisory on this subject.
Class C EPIRBs
These are manually activated devices intended for pleasure craft
which do not venture far offshore and for vessels on the Great Lakes.
They transmit a short burst on VHF-FM channel 16 (156.8 MHz) and
a longer homing signal on channel 15 (156.75 MHz). Their usefulness
depended upon a coast station or another vessel guarding channel
16 and recognizing the brief, recurring tone as an EPIRB. Class
C EPIRBs were not recognized outside of the United States, and were
no longer recognized in the U.S. after 1999.
406 MHz EPIRBs
The 406 MHz EPIRB was designed to operate with satellites. The
signal frequency (406 MHz) has been designated internationally for
use only for distress. Other communications and interference, such
as on 121.5 MHz, is not allowed on this frequency. Its signal allows
a satellite local user terminal to accurately locate the EPIRB (much
more accurately -- 2 to 5 km vice 25 km -- than 121.5/243 MHz devices),
and identify the vessel (the signal is encoded with the vessel's
identity) anywhere in the world (there is no range limitation).
These devices are detectable not only by COSPAS-SARSAT satellites
which are polar orbiting, but also by geostationary GOES weather
satellites. EPIRBs detected by the GEOSTAR system, consisting of
GOES and other geostationary satellites, send rescue authorities
an instant alert, but without location information unless the EPIRB
is equipped with an integral GPS receiver. EPIRBs detected
by COSPAS-SARSAT (e.g. TIROS N) satellites provide rescue authorities
location of distress, but location and sometimes alerting may be
delayed as much as an hour or two. These EPIRBs also include a 121.5
MHz homing signal, allowing aircraft and rescue craft to quickly
find the vessel in distress. These are the only type of EPIRB which
must be certified by Coast Guard approved independent laboratories
before they can be sold in the United States.
A new type of 406 MHz EPIRB, having an integral GPS navigation
receiver, became available in 1998. This EPIRB will send accurate
location as well as identification information to rescue authorities
immediately upon activation through both geostationary (GEOSAR)
and polar orbiting satellites. These types of EPIRB are the
best you can buy.
406 MHz emergency locating transmitters (ELTs) for aircraft are
currently available. 406 MHz personnel locating beacons (PLBs) are
available in Alaska and Canada, and will soon be available throughout
The Coast Guard recommends you purchase a 406 MHz EPIRB, preferably
one with an integral GPS navigation receiver. A Cat I EPIRB should
be purchased if it can be installed properly.
406 MHz GEOSAR System
The major advantage of the 406 MHz low earth orbit system is the
provision of global Earth coverage using a limited number of polar-orbiting
satellite. Coverage is not continuous, however, and it may
take up to a couple of hours for an EPIRB alert to be received.
To overcome this limitation, COSPAS-SARSAT has 406 MHz EPIRB repeaters
aboard three geostationary satellites, plus one spare: GOES-W, at
135 deg W; GOES-E, at 75 deg W; INSAT-2A, at 74 deg E; and INSAT-2B
(in-orbit spare), at 93.5 deg E. Ground stations capable of
receiving 406 MHz. Except for areas between the United Kingdom
and Norway, south of the east coast of Australia, and the area surrounding
the Sea of Okhotsk near Russia, as well as polar areas, GEOSAR provides
continuous global coverage of distress alerts from 406 MHz EPIRBs.
Note that GEOSAR cannot detect 121.5 MHz alerts, nor can it route
unregistered 406 MHz alerts to a rescue authority. GEOSAR
cannot calculate the location of any alert it receives, unless the
beacon has an integral GPS receiver.
COSPAS-SARSAT is an international satellite-based search and rescue
system established by the U.S., Russia, Canada and France to locate
emergency radio beacons transmitting on the frequencies 121.5, 243
and 406 MHZ.
Space System for Search of Distress Vessels (a Russian acronym)
Search and Rescue Satellite-Aided Tracking
Inmarsat E EPIRB
Inmarsat E EPIRBs transmit a distress signal to Inmarsat geostationary
satellites which includes a registered identity similar to that
of the 406 MHz EPIRB and a location derived from a GPS navigational
satellite receiver inside the EPIRB. Inmarsat EPIRBs may be detected
anywhere in the world between 70 degrees North latitude and 70 degrees
South latitude. Since geostationary satellites are used, alerts
are transmitted nearly instantly to a rescue coordination center
associated with the Inmarsat coast earth station receiving the alert.
Alerts received over the Inmarsat Atlantic Ocean Regions are routed
to the Coast Guard Atlantic Area command center in New York, and
alerts received over the Inmarsat Pacific Ocean Region are routed
to the Coast Guard Pacific Area command center in San Francisco.
The Coast Guard urges those owning EPIRBs to periodically examine
them for water tightness, battery expiration date and signal presence.
FCC rules allow Class A, B, and S EPIRBs to be turned on briefly
(for three audio sweeps, or one second only) during the first five
minutes of each hour. Signal presence can be detected by an FM radio
tuned to 99.5 MHz, or an AM radio tuned to any vacant frequency
and located close to an EPIRB. 406 MHz EPIRBs can be tested
through its self-test function, which is an integral part of the
device. 406 MHz EPIRBs can also be tested inside a container
designed to prevent its reception by the satellite. Testing
a 406 MHz EPIRB by allowing it to radiate outside such a container
406 MHz EPIRBs use a special type of lithium battery designed for
long-term low-power consumption operation. Batteries must be replaced
by the date indicated on the EPIRB label using the model specified
by the manufacturer. It should be replaced by a dealer approved
by the manufacturer. If the replacement battery is not the proper
type, the EPIRB will not operate for the duration specified in a
Registration of 406 MHz EPIRBs
Proper registration of your 406 MHz satellite emergency position-indicating
radio beacon (EPIRB) is intended to save your life, and is mandated
by Federal Communications Commission regulations. The Coast Guard
is enforcing this FCC registration rule.
Your life may be saved as a result of registered emergency information.
This information can be very helpful in confirming that a distress
situation exists, and in arranging appropriate rescue efforts. Also,
GOES, a geostationary National Oceanic & Atmospheric Administration
weather satellite system can pick up and relay an EPIRB distress
alert to the Coast Guard well before the international COSPAS-SARSAT
satellite can provide location information. If the EPIRB is properly
registered, the Coast Guard will be able to use the registration
information to immediately begin action on the case. If the EPIRB
is unregistered, a distress alert may take as much as two hours
longer to reach the Coast Guard over the international satellite
system. If an unregistered EPIRB transmission is abbreviated for
any reason, the satellite will be unable to determine the EPIRB's
location, and the Coast Guard will be unable to respond to the distress
alert. Unregistered EPIRBs have needlessly cost the lives of several
mariners since the satellite system became operational.
What happens to your registration form?
The registration sheet you fill out and send in is entered into
the U.S. 406 Beacon Registration Database maintained by NOAA/NESDIS.
If your EPIRB is activated, your registration information will be
sent automatically to the appropriate USCG SAR Rescue Coordination
Center (RCC) for response. One of the first things the RCC watchstanders
do is attempt to contact the owner/operator at the phone number
listed in the database to determine if the vessel is underway (thus
ruling out the possibility of a false alarm due to accidental activation
or EPIRB malfunction), the intended route of the vessel if underway,
the number of people on board, etc., from a family member. If there
is no answer at this number, or no information, the other numbers
listed in the database will be called to attempt to get the information
described above needed to assist the RCC in responding appropriately
to the EPIRB alert.
When RCC personnel contact the emergency phone numbers you provide,
they will have all the information you have provided on the registration
form. You should let these contacts know as much about your intended
voyage as possible (i.e., intended route, stops, area you normally
sail/fish/recreate, duration of trip, number of people going, etc.).
The more information these contacts have, the better prepared our
SAR personnel will be to react. The contacts can ask the RCC personnel
contacting them to be kept informed of any developments, if they
You may be fined for false activation of an unregistered EPIRB.
The U.S. Coast Guard routinely refers cases involving the non-distress
activation of an EPIRB (e.g., as a hoax, through gross negligence,
carelessness or improper storage and handling) to the Federal Communications
Commission. The FCC will prosecute cases based upon evidence provided
by the Coast Guard, and will issue warning letters or notices of
apparent liability for fines up to $10,000.
However, the Coast Guard has suspended forwarding non-distress
activations of properly registered 406 MHz EPIRBs to the FCC, unless
activation was due to hoax or gross negligence, since these search
and rescue cases are less costly to prosecute.
If you purchase a new or a used 406 MHz EPIRB, you MUST
register it with NOAA. If you change your boat, your address, or
your primary phone number, you MUST re-register
your EPIRB with NOAA. If you sell your EPIRB, make sure the purchaser
re-registers the EPIRB, or you may be called by the Coast Guard
if it later becomes activated.
An FCC ship station license is no longer required to purchase or
carry an EPIRB.
or call toll free at 1-888-212-SAVE (i.e. 1-888-212-7283)
for further information or a copy of the registration form. From
outside the U.S., call +1 (301) 457-5430 (fax: (301) 568-8649) for
further information. Forms may be requested by phone or fax, or
downloaded by computer (above).
There is no charge for this service. IT MAY SAVE YOUR LIFE.