ECDIS

Question 1

What does ECDIS stand for?

Answer 1

Electronic Chart Display and Information System

Question 2

What is the primary function of the ECDIS to contribute to safe navigation?

Answer 2

• Sounding alarms to alert watch keepers
• Creating simple process for reliable updating of the ENC and publications
• Reduces the navigational workload of the OOW

Question 3

What is the difference between an ECS and an ECDIS?

Answer 3

An ECS (Electronic Chart System) is not approved and cannot be used as your primary means of navigation whereas ECDIS can be.

Question 4

What is a Raster Chart?

Answer 4

Digital photocopy of an existing paper chart

Question 5

What is the difference between an ENC and a SENC?

Answer 5

• ENC is the data in binary code containing the information of the displayed image
• SENC is the display of the information.

Question 6

What are the 3 main displays of an ECDIS?

Answer 6

Base - used for initial planning only

Standard - minimum required for navigation

All - All features of the display turned on

Question 7

What considerations do you make when setting the safety contour?

Answer 7

• Draft
• Under Keel Clearance (UKC)
• Squat
• Manoeuvrability
• How compact the contours are
• Height of tide (only when required)

Question 8

What are the advantages of an ENC vector chart?

Answer 8

• Intelligent, can be interrogated
• Seamless
• Scalable with no distortion when zooming
• Information layers may be added or removed
• Alarms and Indications
• Ability to monitor own ships route
• Small file size when updating

Question 9

What is the S-52 standard?

Answer 9

Have 2 eyes is for YOU

Determines how ENC data is displayed on an ECDIS screen through symbols, line styles, colours and other visual cues. This means that what the mariner sees on the screen is displayed in the same way across all approved makes and models of ECDIS.

Question 10

What is the S-57 standard?

Answer 10

The current data format used for the exchange of digital hydrographic data between national hydrographic offices, and for its distribution to manufacturers, mariners and other data users.

Question 11

What is safety depth?

Answer 11

Value set by the mariner that is used by ECDIS to portray soundings as black if they are equal to or shallower than the value and grey if they are deeper.

Question 12

What is safety contour?

Answer 12

A specific depth contour set by ECDIS. It marks the boundary between “safe-water” and shallow water with an extra wide isoline and can be used to give an alarm.

Question 13

What is the calculation for safety depth?

Answer 13

Safety depth = Draught + UKC - HOT

Question 14

What are the ECDIS alarms?

Answer 14

CDPAD

• Crossing safety contour
• Deviation from route (crossing XTE)
• Positioning system failure
• Approach to a critical point
• Different geodetic datum

Question 15

What are ECDIS indications?

Answer 15

• Information over-scale (SCAMIN)
• Larger scale ENC available
• No ENC available
• Route planning across safety contour
• Route planning across specified area
• System test failure

Question 16

What are the advantages of ECDIS?

Answer 16

• Reduces OOW workload which means they can spend more time looking out of the window
• Ships position continuously monitored
• Information overlays to increase situational awareness
• Quick and easy route planning
• Automatic log book recording

Question 17

What are the limitations of an ECDIS?

Answer 17

• False sense of security
• GPS could lack accuracy
• Information Overload
• Tendency to obscure view at night
• Over reliance
• Potential old survey information

Question 18

What are the advantages of a RCDS?

Answer 18

• Global coverage
• Familiar as same as paper charts
• Fully approved
• Cheap

Question 19

What are the limitations of RCDS?

Answer 19

• Cluttered when zoomed out
• Different scales
• Not scalable
• No anti-grounding alarms
• Not seamless, has boundaries
• Cannot be interrogated

Question 20

What are some ways to check that our position displayed on ECDIS is our actual position?

Answer 20

• Manual position fixing (visual/radar)
• Look out of the window
• Comparison of ARPA overlay of a fixed mark with the charted position
• Comparison of a radar overlay with conspicuous land or fixed targets
• Observation of a parallel index on the ship radar display to monitor comparison with planned track
• Monitoring the depth shown by the echo sounder when appropriate
• Checking the track history

Question 21

What is meant by integrity monitoring?

Answer 21

To continuously assess the quality and reliability of the electronic chart data being displayed to ensure it meets certain standards

Question 22

What are the ECDIS back-up requirements for yachts under 3000 GT?

Answer 22

• 1x paper chart folio

Or

• 1 x ECDIS unit and 1x paper chart folio

Or

• 2x ECDIS units that work independently with separate power supply and GPS input

Question 23

What is CATZOC?

Answer 23

Category Zone of Confidence are the values that used to highlight the accuracy of data presented on charts.

Question 24

What is Admiralty Vector Chart Service?

Answer 24

(AVCS) is the world’s leading official digital maritime chart service to help bridge crews navigate safely and efficiently whilst meeting flag and Port State requirement’s.

Question 25

What are the inputs required for ECDIS under SOLAS?

Answer 25

- Emergency power source - Gyro compass - Speed log - GPS receiver - Compatible with latest IHO standards

Question 26

How do you know that ECDIS is displaying the correct symbols?

Answer 26

- Check that my ECDIS is up to date - Has correct S-52 presentation library by going to chart number 1 in the middle of the Atlantic and zooming in to the appropriate lat and long and confirming that what I can see on the screen matches my pdf/paper.

Question 27

What happens if you lose your GPS on ECDIS?

Answer 27

ECDIS will go into DR mode and will base your position on your heading and STW

Question 28

Which vessels is it mandatory to have ECDIS?

Answer 28

- All passenger ships over 500GT - All cargo ships over 3000 GT