Recommended texts: Please see Radar Afloat, which is an excellent textbook on the use of radar at sea for workboats and all other vessels. They will help with the Restricted Radar Exams.


This document contains the Maritime Rule Part 32 syllabus for the RESTRICTED RADAR CERTIFICATE. Approved under section 48 of the Maritime Transport Act 1994



Assessment and Examination Arrangements

  1. Objective.
    On completion of the syllabus, the candidate shall:
    1. Be able to demonstrate the correct way to tune a radar set, use the controls, obtain a position of the ship, and avoid collision using radar.
    2. Know the basic theory of radar and its use for position fixing and collision avoidance.

  2. Sea Service.
    A candidate shall have completed 12 months' qualifying service before becoming eligible to sit the examination.

  3. Course.
    A candidate shall normally have attended the full 4 days of the course before being eligible to sit the examination.

    The course shall be conducted to this Maritime Safety Authority syllabus on a site and with facilities and radar equipment approved by the Principal Nautical Examiner.

    The length of the course shall be at least 4 full working days. Three of the days shall be spent on a site close to a shipping channel on the coast or on a radar simulator in order that observations of different types of targets and proper adjustment of controls may be demonstrated. The other day shall be spent aboard a vessel fitted with a radar approved by the Principal Nautical Examiner.

    The vessel shall not be confined to a dock or narrow river but is to be making way with an unobstructed view of a main shipping channel so that students may be taught the techniques of observing moving targets and land echoes in the vicinity.

    The course shall be open to inspection by the Principal Nautical Examiner to ensure that uniform standards are maintained.

  4. Examination.
    The examination will consist of a written and an oral section. The written work shall be marked out of 20; the oral work shall also to be marked out of 20. A candidate who has completed the course shall obtain a combined total of at least 28 marks in order to pass. A candidate who has not completed the course, but who has otherwise completed the syllabus, may have one attempt to pass the examination without completing the course but shall obtain a combined total of at least 36 marks in order to pass.

    Every candidate, shall complete the written question paper in 40 minutes, and shall, in the oral examination, satisfy the examiner that they can:

    1. set up the controls in the correct sequence;
    2. satisfactorily answer one question concerning the function of any one of the controls;
    3. determine whether or not risk of collision exists and take appropriate action; and
    4. correctly identify coastal features on the PPI, locate them on the chart, and obtain a fix.

    The examination shall be conducted on behalf of the Maritime Safety Authority by an approved examiner.

    The examiner shall normally hold a Certificate of Competency as Master Foreign-Going but other qualifications may be approved by the Principal Nautical Examiner, they shall also be the holder of an Electronic Navigation Systems certificate but other equivalent certificates may be approved by the Principal Nautical Examiner. The examiner shall not have been directly concerned with teaching radar to the candidates they are examining.

    Question papers will be compiled and set by the examiner. They are confidential and their contents are not to be divulged for any purpose other than the conduct of the examination. The Principal Nautical Examiner may audit the papers and oral exam from time to time to ensure the standard is maintained.

    A Restricted Radar Certificate will be issued by the examiner to every person who passes the examination.

    An examination candidate may choose to be examined on the main syllabus only and not on items marked as "background". In this case, any Restricted Radar Certificate issued must be endorsed "for ILM use only".

    This option allows individual candidates to choose either

    1. A Restricted Radar Certificate that will be accepted for both ILM and for the higher certificates of NZOW, NZOM, MDSFV and CDSFV, without need to repeat the training and examination to include the background theory; or
    2. A Restricted Radar Certificate that will only be accepted for ILM and will not be accepted for the higher certificates of NZOW, NZOM, MDSFV and CDSFV without re-examination in the full syllabus.
    The examiner shall advise any applicant of these options.


  1. Pulses.
    1. (Background) Understands that if the time taken for a pulse of radio energy to be reflected from an object is known, then the distance to the object is known.
    2. (Background) Knows that radio waves travel at 300 million metres per second.
    3. (Background) Understands the term "wavelength".
    4. (Background) Knows that the 3 cm and 10 cm wavelengths are most suitable for transmitting the brief burst of high energy contained in a radar pulse.
    5. (Background) Appreciates that a radar transmitter is triggered to produce 500 to 4000 pulses per second.
    6. (Background) Knows that the number of pulses per second is the pulse repetition frequency (prf).
    7. (Background) Appreciates the meaning of pulse length.
    8. (Background) Knows that the interval between pulses is much longer than the pulse length.

  2. Aerial.
    1. (Background) Understands that the aerial system has several functions:
      1. It transmits the pulses.
      2. It concentrates the pulses into a narrow beam.
      3. It rotates at a constant speed.
      4. It receives the returning echoes from pulses which have struck a target and returned.
    2. (Background) Knows that the aerial system is called a scanner.
    3. (Background) Appreciates that the scanner cannot transmit and receive at the same time.

  3. Display.
    1. Knows that the returning echoes of the targets are indicated on the display in plan position.
    2. (Background) Appreciates that the radar picture is created by a series of spots moving radially from the centre to the edge of the picture.
    3. (Background) Appreciates that the spot travels from the centre to the edge of the picture at a steady speed depending on the range scale in use.
    4. (Background) Appreciates that the spot leaves the centre of the picture at the same time as the pulse leaves the aerial.
    5. Knows that a returning echo is amplified and creates a "paint" or "echo" on the display.
    6. Knows that the distance from the picture centre to the echo represents the actual distance from scanner to target.

  4. Range.
    1. Knows that a radar's minimum range depends primarily on the pulse length and height of scanner.
    2. Background Knows that range accuracy depends mainly upon:
      1. Spot size.
      2. The uniform speed of the spot moving out from the centre.
    3. Background Knows that accuracy varies with the range scale in use and that range accuracy error should not exceed 1.5 percent of the maximum range of the scale in use.
    4. Knows that the maximum detection range depends upon:
      1. Pulse repetition frequency.
      2. Output power transmitted
      3. Wavelength.
      4. Aerial gain.
      5. Receiver sensitivity.
      6. Height of scanner.

  5. Bearing.
    1. (Background) Appreciates that, as the scanner rotates, the direction of the pulse transmission changes.
    2. (Background) Knows that the scanner rotates at 20 to 30 r.p.m. for 3 cm radar and more slowly for 10 cm radar.
    3. Appreciates that the transmitted pulse spreads out slightly away from the scanner into a lobe or beam.
    4. Understands that the centre line of the lobe indicates the correct bearing but some echoes return from the lobe edges.
    5. Knows that the movement of the spot on the screen is synchronised with the scanner so that the line swept out by the spot rotates around the screen.
    6. Knows the provisions made for obtaining bearings from the display.
    7. Knows that the bearing accuracy depends upon:
      1. Horizontal beam (or lobe) width.
      2. Synchronisation of spot to scanner movement.
      3. Correct centring of the spot.
      4. Correct alignment of the heading marker with the fore and aft line.
      5. Correct alignment of the heading marker with the bearing scale.

  6. Components.
    1. (Background) Shows by block diagram the connections between:
      1. Transmitter unit which generates and triggers the pulse.
      2. Scanner unit including transmit/receive cell.
      3. Mixer and amplifier units.
      4. Display unit.
    2. Appreciates the need for careful shape and design of the wave guide.
    3. Understands the function of the wave guide.
    4. (Background) Understands the function of the transmit/receive cell.
    5. Understands the need to amplify incoming echo signals.
    6. Knows that a larger scanner concentrates the transmitted energy more effectively and has a larger aerial gain.
    7. Understands the terms, "horizontal" and "vertical beam widths".
    8. Appreciates that there will be a loss of echo strength when the vessel rolls beyond half the vertical beam width angle.
    9. Knows that the distance to the radar horizon is governed by the height of the scanner.
    10. (Background) Knows that the distance to the radar horizon in nautical miles is given by 2.21Íh, where "h" is the height of the scanner above sea level in metres.
    11. Understands the cause and effect of shadow sectors.
    12. Appreciates the radiation hazards of radar transmissions.

  7. Controls.
    1. Knows the checks necessary before switching on a radar set.
    2. Knows that the correct sequence to follow when setting up the controls is:
      1. Check scanner is clear and no one is aloft.
      2. Controls all turned down.
      3. Off, standby, on.
      4. Brilliance.
      5. Centring.
      6. Gain.
      7. Tuning.
      8. Sea clutter.
      9. Rain clutter.
    3. Knows the purpose of the off, standby, and run modes.
    4. Knows that there may be delays between the operation of these modes.
    5. Knows the general effect of the brilliance control on the picture.
    6. Knows how to recognise correct and incorrect settings of the brilliance control.
    7. Knows the effect of the centring controls on the picture.
    8. Knows how to recognise correct and incorrect settings of the centring controls.
    9. Appreciates that centring may be preset by the manufacturer.
    10. Knows the general effect of the gain control on the picture.
    11. Knows how to recognise correct and incorrect settings of the gain control.
    12. Knows the general effect of the tuning control on the picture.
    13. Knows how to recognise correct and incorrect settings of the tuning control.
    14. Knows how to tune a radar by using:
      1. A tuning indicator.
      2. A tuning meter.
      3. Sea clutter.
      4. Performance monitor.
      5. The echo of a distant object.
    15. Knows the general effect of the sea clutter control on the picture.
    16. Knows how to recognise correct and incorrect settings of the sea clutter control.
    17. Knows the dangers of using too much sea clutter control.
    18. Knows the general effect of the rain clutter control on the picture.
    19. Knows when the rain clutter control should be used.
    20. Knows the difference between range rings and variable range marker.
    21. Demonstrates how to bring one or both on to the screen and measure the range of a target.
    22. Knows how to check the accuracy of the range markers.
    23. Knows how to recognise a heading marker and why it can be temporarily removed from the picture.
    24. Knows how to recognise an electronic bearing marker and how to bring it on to the screen.
    25. Demonstrates how to take a relative bearing of a target using an electronic bearing marker and a mechanical bearing cursor.
    26. Knows the international symbols for these controls:
      1. Radar off, standby, run.
      2. Gain.
      3. Tuning.
      4. Brilliance.
      5. Range selector.
      6. Anti-sea clutter.
      7. Range rings.
      8. Variable range marker.
      9. Bearing marker.
    27. Uses a working radar to demonstrate the setting up of a good picture on the screen by correct use of the controls.

  8. Presentation.
    1. Knows the principles of, and the differences between, these display modes:
      1. Ship's head up, unstabilised, relative motion.
      2. Course up, compass stabilised, relative motion.
      3. North up, compass stabilised, relative motion.
    2. Knows how to obtain a true bearing of a target in all display modes.
    3. Knows that unstabilised displays will blur when one's own vessel is yawing or altering course.
    4. Knows that when own vessel is making way any target, fixed or moving, will have an apparent motion which will be different from its real motion.

  9. Interpretation.
    1. Defines "aspect" of a target:
      1. In general terms for all targets.
      2. In specific terms for ship targets.
    2. Understands the effect of target aspect on echo strength.
    3. Understands the effect of the shape and surface roughness on echo strength.
    4. Differentiates between the effects on echo strength of: metal, wood, plastic, rock, sand, trees, ice, rain, waves.
    5. Appreciates that large targets return more energy to the scanner and give better echoes than small targets.
    6. Appreciates that radar pulses will only be returned from the nearest side of an object (island, large ship, headland) and the area beyond is not shown on the screen.
    7. Sketches a passive radar reflector or recognises one from a sketch.
    8. Understands why radar reflectors are made of metal and shaped the way they are.
    9. Appreciates the advantages of radar reflectors on navigational marks and small boats.
    10. Knows how to identify sea clutter on the radar picture.
    11. Appreciates that the intensity of sea clutter is affected by wind strength and direction and scanner height.
    12. Knows how to identify rain clutter on the radar picture.
    13. Knows that rain clutter may reduce the strength of echoes from targets beyond the rain.
    14. Defines the term, "radar horizon".
    15. Appreciates that radar pulses continue on into space beyond the radar horizon.
    16. Understands that these pulses may be reflected from a distant hill or mountain beyond the horizon which can cause errors in identification of a distant coastline resulting in errors in position fixing.

  10. False Echoes.
    1. Knows the cause, effects, and ways of identifying second trace returns.
    2. Knows that the scanner produces small side lobes of energy in addition to the main beam.
    3. Understands that side lobes can return echoes and knows ways of identifying and suppressing them.
    4. Knows that pulses may be reflected back and forth between transmitting ship and target before appearing on the screen.
    5. Knows how to identify multiple echoes and suppress them.
    6. Understands that echoes may be returned to the scanner by an indirect path.
    7. Knows how to identify indirect echoes and suppress them.
    8. Knows the cause and effect of "spoking".
    9. Knows the cause and effect of interference from other radar transmissions.

  11. Navigation.
    1. Relates the ship's head up radar picture to the north up chart.
    2. Relates the charted features to the radar picture.
    3. Identifies likely radar conspicuous features from a chart.
    4. Demonstrates ability to fix the vessel's position by any combination of radar ranges and/or bearings.
    5. Knows how to convert a relative radar bearing to a true bearing to put on the chart.
    6. Knows why it is preferable to use ranges rather than bearings when fixing position by radar.
    7. Understands and demonstrates the use of parallel index lines (as engraved on a plastic plate over the display) to:
      1. Indicate the heading to pass clear of charted dangers.
      2. Monitor the track to keep clear of dangers.

  12. Collision Avoidance.
    1. Appreciates the significance of Maritime Rules Part 22 - Collision Prevention -with respect to radar.
    2. Demonstrates how to obtain the range and bearing of a ship echo.
    3. Demonstrates that a series of ranges and bearings should be taken to establish the relative movement of a ship echo.
    4. Appreciates that this information can be recorded on paper, on a reflection plotter or by an auto-plot radar display.
    5. Knows how to determine from the radar if a close quarters situation is developing.
    6. Knows how to determine from the radar if a risk of collision exists.
    7. Knows how to apply the principles of Maritime Rules Part 22 - Collision Prevention - to avoid a close quarters situation.

  13. Human Factors.
    1. Appreciates how what is seen on the radar looks different to what is seen visually or on the chart.
    2. Appreciates the risks of targets not showing on radar.
    3. Appreciates the risks of navigating only using radar.
    4. Appreciates the risks of keeping a lookout by radar only.
    5. Appreciates the possible fatigue caused by watching a radar for a long time.
    6. Understands that, in a multicrew situation, the radar observer has to work in a team with other bridge crew.

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