ECDIS Flashcards
Briefly explain what ECDIS is?
- A type approved Electronic Chart Display and Information System
- complies with IMO performance standards
Briefly explain what ECS is?
ECS - electronic chart system
- ECS is an unapproved system.
- cannot be used as a primary means of navigation.
Briefly explain what RCDS means?
- A digital photographed or scanned copy of an existing paper chart.
- It cannot be used as a Primary means of navigation.
What are the chart carriage requirements under SOLAS V?
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
List seven advantages of Vector charts over Raster charts
- 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
What are the four mandatory inputs to ECDIS?
Position (from GPS)
Heading (Gyro)
Speed (Log)
Depth (sounder)
What is the S52 performance standard about?
The standard of chart content and display on ECDIS
What is the S57 performance standard about?
Digital exchange between hydrographic office and digital data
Explain what is an ENC is
- An Electronic Navigation Chart
- produced by or on the authority of a government
- authorized by the HO
What is meant by SENC?
- An ECDIS converts an ENC into a SENC (System Electronic Navigation Chart)
- for processing and display
List five mandatory ECDIS ALARMS
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- Crossing safety contour
- Deviation from route
- Mandatory sensor failure
- Approach to critical point
- Different geodetic datum
List five mandatory ECDIS warnings (INDICATIONS)
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- Default safety contour
- Information overscale
- Larger scale ENC available
- No ENC available
- System test failure
Interpret the following electronic chart symbols
- 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
List 5 factors to consider when setting a safety contour?
1.Draught of vessel
2.Under Keel Clearance
3.Squat
4. Manoeuvrability
5. Seabed topography
Explain why each of the below should be considered
1.Draught of vessel
2.Under Keel Clearance
3.Height of tide
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
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
How can the radar overlay confirm correct input information to the ECDIS?
When switched on the overlay should match the charted features underneath
- An offset = error in GPS position
- Rotation = indicate error in heading input.
List two methods of correcting electronic charts up to date
- Downloading and transfer to ECDIS by USB
- Receiving update CD by mail and putting into computer
Are Ts & Ps applied to electronic charts? Give reasons for your answer
- 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.
State how you can show Maritime Safety Information (MSI) on an ENC?
Enter the information on the chart in the appropriate place using a MARINERS NOTE
what are the advantages of Raster charts
Advantages -
- global coverage
- familiar
- cheap
- same areas
what are the 3 display options for ECDIS?
Base dispay - Absloute minimum you will see
Standard display - consiting of base display, minimum for navigation
Full display - includes base and standard display
what are some dangers with ECDIS
- Over reliance
- false sense of security
- distort night vision
- information over load
Advantages of ECDIS
- ships position continously displayed
- improved spatial awareness for watch keeper
- station lookout
- info overlays to improve situational awareness