comdtinst m2400.1f - US Coast Guard Response Boat-Medium

6.D. Satellite Ship-to-Shore Distress Alerting.
1. Distress Telex Message. A distress telex message can be sent
by satellite, either with absolute priority in general
communication channels from ship earth stations, or on
exclusive distress and safety frequencies using satellite
EPIRBs.
2. Sending A Distress Message. The operator can send a distress
message automatically on a priority basis by pressing the
distress button on a ship earth station terminal. The system
will preempt a channel and automatically forward the distress
message via a coast earth station to an associated RCC. A
coast earth station is designated in each ocean region to
monitor and check all distress messages to ensure that
proper routing to the appropriate Coast Earth Stations (CES)
is effected.
3. Frequencies. Distress messages sent by satellite EPIRBs may
use either polar orbiting satellite (COSPAS-SARSAT) in the
406 - 406.1 MHz band or geostationary satellites (INMARSAT)
that operate in the 1645.5 - 1646.5 MHz band, provided the
INMARSAT service is funded and becomes available.