GMDSS- VHF/DSC LAB WORKSHEET || 100% VALID
SOLUTIONS.
List two U.S. government agencies that regulate/ monitor marine VHF radios correct answers
The FCC regulates marine communications in cooperation with the USCG, which monitors
marine distress frequencies continuously to protect life and property. All users of marine radio,
whether voluntary or compulsory, are responsible for observing both FCC and USCG
requirements
In a marine emergency, why should cell phones be used with caution? correct answers Cell
phones generally cannot provide ship to ship safety communications or communications with
rescue vessels. If you make a distress call on a cell phone, only the one party you call will be
able to hear you.
Most cell phones are designed for a land-based service. Their coverage offshore is limited, and
may change without notice.
Locating a cell caller is hard to do. If you don't know precisely where you are, the USCG will
have difficulty finding your location on the water.
Describe Sea Area A1 correct answers Area within the radiotelephone coverage of at least one
VHF coast station in which continuous DSC alerting and radiotelephony services are available.
Such an area could extend typically 30 nm to 40 nm from the Coast Sation.
What is the typical range of your marine VHF radio? correct answers Line of sight
With the advent of the GMDSS and DSC technology, is a listening watch on VHF Ch. 16 still
necessary? correct answers Yes
What condition(s) can result in much greater ranges with your VHF radio? correct answers
Atmospheric ducting
Explain the unwanted effect of turning a VHF radio's squelch too high. correct answers Limits
effective receiving range
, What is the emissions class designation for VHF voice and DSC? What does the designation
indicate? correct answers Voice- F3E, DSC-G2B
What is the mandatory GMDSS VHF DSC watch channel/frequency? correct answers Ch 70,
156.525 MHz
List the minimum voice VHF channels required under the GMDSS correct answers 16, 13, 6, 70
What does the term follow-on channel or frequency mean when referring to DSC calling? correct
answers The channel where the actual information is exchanged.
Briefly describe Resuce 21 correct answers Rescue 21 is an advanced maritime computing,
command, control, and communications (c4) system designed to manage communications for the
USCG.
What types of radio communications are prohibited by the FCC? correct answers False distress
or emergency messages. Messages containing obscene, indecent, or profane words or meaning.
General calls, signals, or messages on channel 16, except in an emergency or if you are testing
your radio (these are messages not addressed to a particular station), or when your ship is on land
(for example, while the ship is on a trailer).
What may happen if you violate the U.S.'s Communications Act or FCC rules? correct answers If
the FCC finds that you have willfully or repeatedly violated the Comms. Act or the rules, your
authorization to use the radio may be revoked and you may be fined or sent to prison.
Explain the difference between an ALpha VHF channel and an International VHF channel. Why
is it important to understand the difference? correct answers Note that the letter "A" indicates
simplex use of the ship station transmit side of an international duplex channel, and that
operations are different than international operations on that channel. Some VHF transceivers are
equipped with an " International-U.S." swith for that purpose. "A" channels are generally only
used in the U.S. and use is normally not recognized or allowed outside the U.S. The letter "B"
indicates simplex use of the coast station transmit side of an international duplex channel. The
U.S. does not currently use "B" channels for simplex communications in this band.
SOLUTIONS.
List two U.S. government agencies that regulate/ monitor marine VHF radios correct answers
The FCC regulates marine communications in cooperation with the USCG, which monitors
marine distress frequencies continuously to protect life and property. All users of marine radio,
whether voluntary or compulsory, are responsible for observing both FCC and USCG
requirements
In a marine emergency, why should cell phones be used with caution? correct answers Cell
phones generally cannot provide ship to ship safety communications or communications with
rescue vessels. If you make a distress call on a cell phone, only the one party you call will be
able to hear you.
Most cell phones are designed for a land-based service. Their coverage offshore is limited, and
may change without notice.
Locating a cell caller is hard to do. If you don't know precisely where you are, the USCG will
have difficulty finding your location on the water.
Describe Sea Area A1 correct answers Area within the radiotelephone coverage of at least one
VHF coast station in which continuous DSC alerting and radiotelephony services are available.
Such an area could extend typically 30 nm to 40 nm from the Coast Sation.
What is the typical range of your marine VHF radio? correct answers Line of sight
With the advent of the GMDSS and DSC technology, is a listening watch on VHF Ch. 16 still
necessary? correct answers Yes
What condition(s) can result in much greater ranges with your VHF radio? correct answers
Atmospheric ducting
Explain the unwanted effect of turning a VHF radio's squelch too high. correct answers Limits
effective receiving range
, What is the emissions class designation for VHF voice and DSC? What does the designation
indicate? correct answers Voice- F3E, DSC-G2B
What is the mandatory GMDSS VHF DSC watch channel/frequency? correct answers Ch 70,
156.525 MHz
List the minimum voice VHF channels required under the GMDSS correct answers 16, 13, 6, 70
What does the term follow-on channel or frequency mean when referring to DSC calling? correct
answers The channel where the actual information is exchanged.
Briefly describe Resuce 21 correct answers Rescue 21 is an advanced maritime computing,
command, control, and communications (c4) system designed to manage communications for the
USCG.
What types of radio communications are prohibited by the FCC? correct answers False distress
or emergency messages. Messages containing obscene, indecent, or profane words or meaning.
General calls, signals, or messages on channel 16, except in an emergency or if you are testing
your radio (these are messages not addressed to a particular station), or when your ship is on land
(for example, while the ship is on a trailer).
What may happen if you violate the U.S.'s Communications Act or FCC rules? correct answers If
the FCC finds that you have willfully or repeatedly violated the Comms. Act or the rules, your
authorization to use the radio may be revoked and you may be fined or sent to prison.
Explain the difference between an ALpha VHF channel and an International VHF channel. Why
is it important to understand the difference? correct answers Note that the letter "A" indicates
simplex use of the ship station transmit side of an international duplex channel, and that
operations are different than international operations on that channel. Some VHF transceivers are
equipped with an " International-U.S." swith for that purpose. "A" channels are generally only
used in the U.S. and use is normally not recognized or allowed outside the U.S. The letter "B"
indicates simplex use of the coast station transmit side of an international duplex channel. The
U.S. does not currently use "B" channels for simplex communications in this band.
