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Most of today’s 2 meter units have capable receive of the VHF marine band.  Monitoring marine channels can be interesting. Sometimes on working channels during fishing tournaments you will hear rivalry between captains and liar reports, such as we are not catching anything when they actually have a very good fishing spot.

Channel 16 (156.800 MHz) is a calling and an international distress channel. Channel 22A 157.100 MHz is for marine safety information after first establishing communication on channel 16.   1

When a transmission begins with Securite (pronounced saycuritay) it indicates important safety information is to follow, such as people or vessels in distress, objects or events that can be a danger to navigation.

Meteorological warnings may also follow securite such as hurricane information. Securite normally is used by Coast Guard stations but individuals may broadcast securite messages where appropriate such as a vessel adrift or unable to maneuver in shipping lanes.

Pan-Pan (pronounced pahn, pahn) is the second most important call used when there is an emergency aboard a vessel.  Examples would be injuries, imminent collision or being unsure of location.

Mayday is the most important call such as a threat to life or a vessel.  Examples would be death, collision, and fire at sea.   2   One of the most dangerous places to have a fire is at sea.  Fire drills are performed on cruise ships before the ship leaves the initial port.  

Carnival Cruise Lines will scan your sail and sign card to make certain everyone went to their proper muster station for a required safety briefing. Other cruise lines have similar required safety drills.

Proper call procedure examples are as follows:  Securite x3, all stations x3, this is (ship/station) x3, Securite, name, call sign, position, nature of safety message, other information, out.

Occasionally you may hear false distress calls which are illegal, and a waste of valuable resources and finances.  Improperly handled EPIRBS (emergency beacon transmitters) may set off a false distress call.

Most pleasure boating accidents occur on sunny days when the weather is excellent when alcohol, carelessness or in attention is involved.  3

Reference:
1.            Chapman Piloting, 62nd edition, page 550
2.            Wikipedia:  S’ecurite’ (securite)

3.            United States Power Squadron Boating Safety Course

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Marine Radar

By Ross Goodall, WD4NJV

Marine radar is an important part of a marine electronics suite which may include chart plotters, sonar, two-way marine radio,  a GNSS global navigation satellite system, GPS global positioning system and SART search and rescue transponder.

Some of us have had the chance to visit the bridge of ships that we have been on such as deep-sea fishing boats and cruise lines.  If the captain is not busy, you may be invited to observe radar in use.

I was given the opportunity to pilot (under close supervision) a two-deck commercial passenger boat in the narrow confines of the southern St. Johns River where I received an introduction to Radar.
GROL licensing has a marine radar endorsement this is available.

Marine radars use X band 7.0-11.2 GHz or S band 1.55 GHz-5.2 GHz to detect ships or land obstacles and to provide bearing and distance.

Marine radar uses a rotating antenna to sweep a narrow beam of microwaves out and to listen back for the reflected signal.  The main controls on marine radar are used to adjust gain, clutter, brightness, and contrast.

There are two main types of marine radar.  Pulse and broadband radar.  Pulse radar sends out rapid pulses of energy from a magnetron and reflections are received back.  A mathematical calculation is done by the unit to calculate the distance. Broadband radar sends a continuous wave that increases in frequency as it moves away from the antenna, hitting a target and is reflected back.

Power and beam width determine the distance of what can be seen.  More power will reach further distances. Low power units cannot be expected to see more than 16 to 20 miles and weak returns from a fiberglass boat probably will not show up much more than a mile or two away.  Two KW units can see up to 20 miles.  The curvature if the earth also affects the distance that can be seen. 

Mounting the unit as high as possible will allow the radar to see a longer distance.

The formula that expresses the relationship between the height of the target and the height of the antenna: (1.22 nautical miles X square root of height of radar) +(1.22 nautical miles X square root height of the target)

No matter how powerful the radar unit is and how narrow the beam width is, the radar will not be able to see beyond the equation. Increase the gain If you are looking for more distant targets.  When blips appear and disappear, especially on the windward side, you are picking up waves.  Small dots moving fast and erratically may indicate birds.

Today’s radar is so user friendly that you may run it on the auto mode.  If you are new to marine radar, you may want to, on a sunny and clear day, observe the screen to become proficient.  1

The major marine radar manufacturers are Garmin, Furuno, Raymarine, Lorance and Simrad.  All have excellent detailed websites and "how to" videos.

RF safety is also an important consideration when using marine radar.  During a deep-sea fishing boat trip, I observed a passenger very close the radar unit. Not good.

References

1              Boats.com:   How to use Radar

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