STCW Communication Systems 4

Question 1

What does 'MMSI' stand for in the context of maritime communications?

Accepted Answer

Maritime Mobile Service Identity

Answer

MMSI stands for Maritime Mobile Service Identity, a unique nine-digit number assigned to a ship's radio station for DSC and AIS identification.

Question 2

On which VHF channel should a vessel call a US port authority or vessel traffic service?

Accepted Answer

Channel 12 or 14

Answer

VHF Channels 12 and 14 are commonly used by US port authorities and vessel traffic services (VTS) for ship movement coordination.

Question 3

What is the significance of the 'silence period' observed twice each hour on 2182 kHz?

Accepted Answer

Three-minute periods reserved for listening for distress signals

Answer

At H+00 and H+30, a three-minute radio silence is observed on 2182 kHz so that weak distress signals can be heard without interference.

Question 4

A vessel in Sea Area A2 must carry which mandatory GMDSS equipment in addition to Sea Area A1 equipment?

Accepted Answer

MF DSC radio capable of transmitting on 2187.5 kHz

Answer

Sea Area A2 extends MF coverage, requiring an MF DSC radio able to transmit distress alerts on 2187.5 kHz and watch on 2182 kHz.

Question 5

What is the purpose of AIS (Automatic Identification System) in maritime communications?

Accepted Answer

To automatically broadcast vessel identity, position, course, and speed to nearby ships and coast stations

Answer

AIS continuously broadcasts vessel identity, position, course, speed, and other data, enhancing situational awareness and collision avoidance.

(STCW) Standards Certification and Watchkeeping for Seafarers Practice Test