GMDSS Flashcards

Question

After a DSC distress alert, which associated working channel/frequency do you switch to for VHF, MF, and HF? ⭐

Answer 1

VHF: 70 → 16. MF: 2187.5 → 2182 kHz. HF: DSC channel in a given band → corresponding voice distress frequency in that band.

Answer 2

Distress, Urgency, Safety, Routine; may be all-ships, individual, or group calls.

Answer 3

4207.5 / 6312 / 8414.5 / 12577 / 16804.5 kHz.

Answer 4

4125 / 6215 / 8291 / 12290 / 16420 kHz.

Answer 5

A category of essential safety-related information transmitted via GMDSS (NavWarnings, Met warnings/forecasts, SAR info, other urgent safety info).

Answer 6

They disseminate MSI and coordinate rescue efforts

Answer 7

Chapter IV - Radiocommunications

Answer 8

Automatic MSI receiver on 518 kHz (English) and 490 kHz (national language); select stations (B1) and message types (B2) as needed.

Answer 9

Inmarsat-C provides text distress/safety/routine services; SafetyNET is the Inmarsat MSI broadcast service used especially in A3.

Answer 10

Distress > Urgency > Safety > Routine (automatic queueing/precedence).

Answer 11

Some flags/classes no longer require HF NBDP for distress/safety where satellite GMDSS is carried; confirm flag/class policy for your ship.

Answer 12

Mount as high as possible, vertical polarisation, clear of obstructions/other antennas, and use good quality coax with minimal loss.

Answer 13

MF/HF antenna

Answer 14

Long whip/wire with Antenna Tuning Unit close to the feed point, short/wide copper earth strap to RF ground, secure weatherproofing/insulation.

Answer 15

As high as possible on the vessel, clear of obstructions and away from sources of interference

Answer 16

It’s the return path the antenna works against (hull/ground plate). Poor bonding/ground = poor radiation and range.

Answer 17

Receives alerts, coordinates SAR, tasks units, communicates with OSC (On-Scene Coordinator) and ships.

Answer 18

Record daily/weekly/monthly tests; all distress/urgency/safety comms; MSI reception; any false alerts and corrective actions.

Answer 19

Cancel immediately on the same system/frequency with ID, position, time, and explanation; notify nearest RCC; log the incident.

Answer 20

Send distress by most effective means, maintain watch, coordinate with RCC/assist if able, log all actions/comms.

Answer 21

406 MHz Cospas-Sarsat alert with GNSS position; float-free HRU + auto-activation; many include 121.5 MHz homing.

Answer 22

Transmit ≥48 h; conduct self-tests only; service/replace battery before expiry/after use; ensure registration is current with flag/authority.

Answer 23

9 GHz X-band responder; when interrogated shows 12 dots (or concentric arcs when close) leading rescuers to survivors.

Answer 24

About 5–10 nm to X-band radar (depends on antenna height/conditions).

Answer 25

AIS-SART transmits survivor position as an AIS target to nearby AIS receivers; complementary to radar SART.

Answer 26

Passenger ships & cargo ≥500 GT: ≥3 units. Cargo 300–<500 GT: ≥2 units. Stow for rapid embarkation.

Answer 27

≥8 h at rated power on a 1:9 duty cycle (6 s TX / 6 s RX above squelch / 48 s standby). Keep primary (sealed) batteries in date.

Answer 28

Passenger ships & cargo ≥500 GT: 2. Cargo 300–<500 GT: 1. Stow so one per side is readily available

Answer 29

Use SART/AIS-SART in raft/boat for locating; use handheld VHFs on Ch 16/06 per RCC/OSC instructions for close-quarters SAR comms.

Answer 30

≥12 rocket parachute flares stowed on or near the navigation bridge (SOLAS/LSA Code compliant).

Answer 31

≥4 projectiles each capable of carrying a line ≥230 m in calm weather; ≥4 lines (≥2 kN breaking strength); clear instructions.

Answer 32

Red hand flares: close-range pinpointing, night/day (hold downwind). Orange buoyant smoke: daytime location marking, approach guidance.

Answer 33

Rises ≥300 m, bright red ≥40 s, ≥30,000 cd average, descent ≤5 m/s under parachute; water-resistant, instructions printed.

Answer 34

E.g., Morse SOS by any method; spoken “MAYDAY”; NC flags; square flag above a ball; continuous fog signal; red rocket/hand flares; orange smoke; flames; slowly raising/lowering arms; (also EPIRB/DSC/SART are listed).

Answer 35

Orange canvas panel with a black square & circle (or similar) and dye markers to colour the water.

Answer 36

Primary sealed batteries in date, rechargeable packs + chargers for drills, spare antennae/mics as carried; mark sets with ship name/call sign.

Answer 37

Daily: DSC watch/power checks. Weekly: EPIRB/SART self-tests; VHF/MF/HF test calls. Monthly: Battery condition, antenna/lead inspections; update test log.

Answer 38

Float-free bracket clean/secure, HRU in date, lanyard properly made fast, no obstructions to float-free path, beacon ID/registration verified.

Answer 39

Fuses, lamps/indicators, headset/mics, coax/adaptors, ATU spares, manuals, insulated tools, test loads where applicable.

Answer 40

Alert (DSC/EPIRB/Inmarsat) → Voice MAYDAY → Deploy locating aids (SART/AIS-SART, pyros) → Maintain/coordinate comms with RCC/OSC.

Answer 41

Legacy method—no longer primary in GMDSS; may still be encountered; focus on DSC for alerting.

Answer 42

NAVTEX: coastal MSI (A1/A2 areas and where service exists). SafetyNET (Inmarsat-C): ocean-area MSI (esp. A3) and where NAVTEX not provided.

Answer 43

Links MMSI/hex ID to current ship & contacts so RCC can verify alerts quickly and coordinate SAR; update after surveys/ownership changes.

Answer 44

Lower HF bands travel farther at night (better skywave); higher bands improve by day—choose the band that best supports path length.

Answer 45

Position of vessel Completion of daily tasks Master's signature

Answer 46

Volume Three

Answer 47

They will enter their name, and General Operator's Certificate (GOC) number into Section B of the GMDSS log book

Answer 48

All cargo vessels over 300GT on international voyages

Answer 49

All passenger vessels on international voyages, regardless of tonnage

Answer 50

Form R is the 'Record of Equipment'. It is attached to the Cargo Ship Safety Radio Certificate and details the radio equipment carried onboard the vessel

Answer 51

The person responsible for emergency communications and the person responsible for maintenance. They may be the same person.

Answer 52

No. All stress or urgency messages must be authorised by the Master, although it is likely that the responsible person will transmit the message.

Answer 53

Because they have limited or no signal even a short distance offshore and, even when there is signal, do not alert vessels in the vicinity

Answer 54

The part of the wave that is touching the ground slows due to diffraction and therefore bends downwards. This keeps the wave in contact with ground and allows it to follow the curvature of the earth.

Answer 55

Sky waves are alternately refracted downwards by ionised layers in the ionosphere and upwards again by the earth's surface causing them to 'bounce' large distances beyond the horizon

Answer 56

DSC transmissions are digital which means they have a greater range and differ less from interference. They are also received by DSC radio equipment which is always listening and will THEN sound an alarm to alert the OOW.

Answer 57

Simplex, you can only transmit or receive at alternate time. Duplex can receive and transmit at the same time (like a phone call)

Answer 58

All stations can hear all communications

Answer 59

You must listen first before transmitting and working must not exceed one minute

Answer 60

After no less than 5 minutes. Further attempts must wait at least 15 minutes

Answer 61

It is used as a response when the identity of the station calling you is unknown

Answer 62

SOLAS, Chapter IV - Radio communications

Answer 63

Passenger vessels

Answer 64

Two. A Ship Earth Station and a duplicate which typically also acts as the EGC receiver.

Answer 65

An MF/HF radio (capable of DSC, voice and text) and an EGC receiver. the EGC requirement may be satisfied through carriage of an Inmarsat terminal or by using Telex function of MF/HF

Answer 66

Through Telex/NBDP functionality of the MF/HF radios

Answer 67

Maritime Broadcast and data Protocol. The communication protocol used in Inmarsat C to broadcast MSIs

Answer 68

every 4 hours

Answer 69

Volume V of ALRS

Answer 70

The OOW must read the message and ascertain whether or not it relates to the vessel and its passage plan. if so, the Master must be informed so that appropriate action can be taken.

Answer 71

The zone in which the transmissions from HF radios will not be picked up at ground level

Answer 72

Because UV radiation from the sun affects the amount of refraction which will occur when the HF electromagnetic waves hit the ionosphere and thus affects the distance covered by each 'bounce'

Answer 73

It is the Inmarsat system which uses satellites to disseminate MSI to vessels

Answer 74

The space, ground and mobile segments

Answer 75

It is the iridium system which uses satellites to disseminate MSI to vessels

Answer 76

21 of each

Answer 77

The battery charger should be switched off and the voltage monitored to ensure it doesn't start to drop

Answer 78

Vessels that are equipped with two or more VHF DSC radios will normally conduct the external DSC weekly test by sending a transmission from one unit to the other and back again

Answer 79

To prevent unintended activation of their SART, which will drain the battery

Answer 80

The latitude and longitude of their position, determined using a built-in GNSS receiver

Answer 81

COSPAS SARSAT

Answer 82

An AIS transponder and a GNSS receiver

Answer 83

They musty be mounted in float free housing and activated automatically when in contact with water, in addition to have the facility to be activated manually

Answer 84

By triangulation using 'doppler shift' as satellites pass overhead. This process can take several hours

Answer 85

It should be visually inspected to ensure it is in good condition and a self test should be conducted in accordance with the manufacturer's instructions

Answer 86

The EPIRB and its float-free mounting should be visually inspected to ensure that they remain in good condition. A self-test of the unit should be conducted, in accordance with the manufacturer's instructions

Answer 87

In Annex IV of the IRPCS

Answer 88

By sending a distress-priority message to the same LES through which the accidental alert was sent.

Answer 89

Tune to the indicated frequency, listen to the message and respond accordingly. They should not acknowledge receipt by DSC

Answer 90

The frequency or channel on which the safety message will be transmitted

Answer 91

A call is intended to draw other vessels' attention to the transmission, whereas the message contains important information relating to the situation

Answer 92

By voice only

Answer 93

Acknowledging a DSC distress alert will stop the alert and may mean that the vessel does not receive the assistance it requires. Silencing an alert to stop the alarm locally is different from acknowledging it

Answer 94

When they sight a distressed party who are unlikely to be able to send their own distress message

Answer 95

They should set watch on 2182kHx and acknowledge by RT immediately

Answer 96

1. Make an entry in the GMDSS log book 2. Acknowledge by distress radiotelephony only 3. relay the message to the appropriate coast station by any available means 4. proceed at best speed to the position of the vessel in distress

Answer 97

Vessels operate in inland waterways in counties party to the agreement

Answer 98

A unique Fast Frequency Shift Keying data signal, heard as a scratchy noise at the end of every transmission. This signal contains a unique ATIS call sign which identifies the vessel.

Answer 99

SOS (... --- ...)

Answer 100

I have a diver down. Keep well clear

Answer 101

They may be fitted with RACON (radar transponders) which create morse code patterns of dots and dashed on a vessel's radar screen

Answer 102

45 seconds

Answer 103

for 1 hours more than the requires period for emergency generator

Answer 104

300-400nm from the relevant NAVTEX station

Answer 105

Admiralty List of Radio Signals (ALRS)

GMDSS Flashcards

(156 cards)