General

Question 1

What is Dual Watch?

Answer 1

Monitoring working channel and Ch 16 simultaneously. Ch 16 takes priority if VHF can not handle Dual watch.

Question 2

What is a Simplex channel?

Answer 2

One aerial, one frequency. Found in nearly all leisure and small workboats. Transmission is one way at a time, i.e TALK or LISTEN not both

Question 3

What is a Duplex channel?

Answer 3

Two aerials and two frequencies needed. Transmissions and reception take place simultaneously Used for shore-shore or ship- shore (never ship-ship)

Question 4

What is the range of VHF?

Answer 4

Approximately 35NM

Question 5

What is the biggest determining factor of VHF range?

Answer 5

Height of aerial

Question 6

What wave is VHF?

Answer 6

Direct Wave (Line of sight)

Question 7

What wave is MF?

Answer 7

Ground Wave (through earth)

Question 8

What wave is HF?

Answer 8

Sky wave (Bouncing of Ionosphere)

Question 9

What is radio propagation?

Answer 9

Radio waves range affected by refraction
1. Normal refraction
2. Super-refraction
3. Sub-refraction
4. Ducting

Question 10

What is Capture effect?

Answer 10

The full suppression of the weaker signal at the receiver’s limiter (if one exists), where the weaker signal is muted rather than amplified

Question 11

What is the maximum permitted power for VHF, MF & HF?

Answer 11

VHF - 25 watts
MF - 400 watts
HF - 1500 watts (1.5 kW)

Question 12

What does ITU stand for?

Answer 12

International Telecommunications Union

Question 13

What SOLAS chapter is Radio Communications?

Answer 13

SOLAS IV (4) - Radio communications

Question 14

Which ships need to comply with SOLAS requirements for GMDSS? (2 factors)

Answer 14

1. Vessels over 300 GT on international voyages or in the open sea
2. Passenger vessels carrying more than 12 passengers on international voyages or in the open sea

Question 15

What should GMDSS ships be capable of?

Answer 15

1. Transmit ship to shore distress alerts by at least 2 independent means
2. Receive shore to ship distress alerts
3. Transmit and receive ship to ship distress alerts
4. Transmit and receive SAR co-ordinating communications
5. Transmit and receive on-scene communications
6. Transmit and receive (homing) signals for location finding
7. Receiving maritime safety information
8. Transmitting and receiving general radio-communications relating to the management of the vessel
9. Transmitting and receiving bridge to bridge communications

Question 16

What is the order of information of a shipping forecast?

Answer 16

1. Gale
2. Wind
3. Sea state
4. Weather
5. Visibility

Question 17

Which NAVTEX information can we not de-select?

Answer 17

ABDL
A - Nav Warnings
B - Met Warnings
D - SAR Information
L - Additional Nav Warnings