ECDIS

Question 1

Briefly explain what ECDIS is?

Answer 1

• A type approved Electronic Chart Display and Information System
• complies with IMO performance standards

Question 2

Briefly explain what ECS is?

Answer 2

• An electronic chart system which is unapproved.
• cannot be used as a primary means of navigation

Question 3

Briefly explain what RCDS means?

Answer 3

• A Raster Chart Display System is one displays raster charts.
• It cannot be used as a Primary means of navigation.

Question 4

What are the chart carriage requirements under SOLAS V?

Answer 4

ECDIS ENCs - required, no paper charts if authorised as primary means of navigation

ECS - Full paper chart coverage required for the voyage

RCDS - per chart coverage required

Question 5

List seven advantages of Vector charts over Raster charts

Answer 5

• Seamless join between charts
• Safety depth and safety contour alarm
• Chart features can be interrogated
• Layers can be selected by the user
• Charts can be rotated to any angle
• Links are possible to extra information
• A choice of symbology for buoyage

Question 6

What are the three mandatory inputs to ECDIS?

Answer 6

Position (from EPFS)
Heading (e.g.. Gyro)
Speed (Log)

Question 7

What is the S52 performance standard about?

Answer 7

The standard of chart content and display on ECDIS

Question 8

What is the S57 performance standard about?

Answer 8

Digital exchange between hydrographic office and digital data

Question 9

Explain what is an ENC is

Answer 9

• An Electronic Navigation Chart
• produced by or on the authority of a government
• authorized by the HO

Question 10

What is meant by SENC?

Answer 10

An ECDIS converts an ENC into a SENC (System Electronic Navigation Chart)
for processing and display

Question 11

List five mandatory ECDIS alarms,

Answer 11

• Crossing safety contour
• Deviation from route
• Mandatory sensor failure
• Approach to critical point
• Different geodetic datum

Question 12

List five mandatory ECDIS warnings (indications)

Answer 12

• Default safety contour
• Information overscale
• Larger scale ENC available
• No ENC available
• System test failure

Question 13

Interpret the following electronic chart symbols

Answer 13

Limit between unofficial vector data and official ENC data

A1 Category Zone of Confidence (5m accuracy)

Generic Isolated Danger symbol (less depth than safety contour)

Sounding of low accuracy

Additional information or picture is available

Question 14

44. List three factors to consider when setting a safety contour?

Answer 14

1.Draught of vessel
2.Under Keel Clearance
3.Height of tide

Question 15

Explain why each of the below should be considered

1.Draught of vessel
2.Under Keel Clearance
3.Height of tide

Answer 15

1.This affects how far below the water line the seabed must be

2.This gives an additional margin of safety, squat should be considered

3.This gives additional water above Chart Datum that can be used

Question 16

how, using a sketch, how safety depth relates to safety contour if the safety depth has been calculated to be 8m and the safety contour is 10m

Answer 16

Question 17

47. How can the radar overlay confirm correct input information to the ECDIS?

Answer 17

When switched on the overlay should match the charted features underneath

• An offset- error in GPS position
• rotation- indicate error in heading input.

Question 18

49. List two methods of correcting electronic charts up to date

Answer 18

• Downloading and transfer to ECDIS by USB
• Receiving update CD by mail and putting into computer

Question 19

Are Ts & Ps applied to electronic charts? Give reasons for your answer

Answer 19

• Some are, it depends on the country of origin. UKHO apply Ts & Ps as corrections.
• Other hydrographic offices apply them.
• Details can be found online.

Question 20

State how you can show Maritime Safety Information (MSI) on an ENC?

Answer 20

Enter the information on the chart in the appropriate place using a MARINERS NOTE