NZ MVOC (VHF Radio) flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Channel 16

The international marine VHF distress, safety and calling channel at 156.800 MHz. Use it to establish contact, then move to a working channel for routine traffic.

MAYDAY

The spoken distress signal used when a vessel or person is in grave and imminent danger and immediate assistance is required. Sent on Channel 16, repeated until acknowledged.

PAN PAN

The urgency signal used for important messages about a vessel or person that is not in immediate grave danger but needs urgent attention or assistance.

SECURITE

The safety signal used to announce navigational warnings, weather warnings or other safety information. Pronounced "say-cure-e-tay".

SILENCE MAYDAY

The phrase used to impose radio silence on Channel 16 during distress traffic. Only stations involved in the distress may transmit until silence is finished.

MAYDAY RELAY

The prefix used when relaying a distress call from another station or when a coast station relays a distress to a rescue asset. Include the original distress details.

Phonetic alphabet

The ITU spelling alphabet (Alfa, Bravo, Charlie ... Zulu) used to spell out difficult words and names clearly over the radio.

Over and Out

"Over" invites a reply; "out" ends the contact with no reply expected. Never say "over and out" because the two contradict each other.

Channel 70

The DSC (Digital Selective Calling) channel at 156.525 MHz. It is reserved for digital distress and calling alerts; voice transmission is not permitted.

DSC

Digital Selective Calling. A digital alert system that sends the vessel's MMSI, position and nature of distress to other stations without using voice.

MMSI

Maritime Mobile Service Identity. A nine-digit number issued for DSC-equipped vessels, programmed into the radio and used for DSC alerts and AIS.

MVOC

Marine VHF Radio Operator Certificate issued in New Zealand after an approved course and assessment. It covers VHF operation, distress procedures and regulations.

RCCNZ

Rescue Coordination Centre New Zealand. The authority that coordinates maritime search and rescue in the New Zealand search and rescue region, reachable via coast stations or directly.

EPIRB

Emergency Position Indicating Radio Beacon. A 406 MHz satellite beacon that alerts rescue authorities with the vessel identity and position when activated.

Channel 6

The intership safety channel at 156.300 MHz, used for safety communications between vessels, including search and rescue coordination.

Channel 13

The bridge-to-bridge channel at 156.650 MHz, used for navigation safety communications between vessels, especially in confined waters.

VHF range

Marine VHF is essentially line-of-sight. Range is typically 15–30 nautical miles depending on antenna height and conditions, and is much less at low antenna height.

Low power

The 1 W setting on a marine VHF radio. Use low power for short-range communications to reduce interference; use high power (25 W) when range is needed.

Radio silence

A condition imposed with "SILENCE MAYDAY" during distress traffic. Only stations involved in the distress may transmit until "SILENCE FINISHED" is given.

False distress

A MAYDAY or DSC distress alert sent when no grave and imminent danger exists. It is an offence and can divert rescue assets from real emergencies.

Distress priority

The order of priority for radio traffic: distress (MAYDAY) first, then urgency (PAN PAN), then safety (SECURITE), then routine traffic.

Position report

In a distress or urgency call, give position in latitude and longitude if known, otherwise as a bearing and distance from a charted landmark.

Persons on board

The number of people on the vessel, stated in a distress or urgency call. It determines the size and type of rescue response.

Nature of distress

A short statement of the problem, such as sinking, fire, grounding, collision or medical emergency, given in a MAYDAY call.

Working channel

A VHF channel other than 16 used for routine conversation after initial contact is made on Channel 16.

Radio check

A request to a coast station or another vessel to confirm your signal is readable. Conducted on a working channel, not on Channel 16.

Maritime Radio

The New Zealand coast radio service that maintains a listening watch on Channel 16 and can relay distress traffic to RCCNZ.

Search and rescue region

The sea area for which New Zealand is responsible for coordinating search and rescue. RCCNZ coordinates responses within this region.

DSC distress button

A covered button on a DSC radio that sends a distress alert with the vessel's MMSI and position. Follow it with a voice MAYDAY on Channel 16.

Ship station licence

The licence required to operate a marine VHF transmitter. Check current Maritime NZ and RSM requirements for your vessel and radio.

AIS channels

Channels 87B (161.975 MHz) and 88B (162.025 MHz) are reserved for Automatic Identification System data; do not use them for voice.

Antenna height

The most important factor in VHF range. A masthead antenna gives the best line-of-sight range; a low antenna greatly reduces it.

Medical emergency

A medical situation may be handled as PAN PAN urgency if not immediately life-threatening, or as MAYDAY if grave and imminent danger exists.