ECDIS Flashcards
What does ECDIS stand for?
Electronic Chart Display and Information System
What is the primary function of the ECDIS to contribute to safe navigation?
- Sounding alarms to alert watch keepers
- Creating simple process for reliable updating of the ENC and publications
- Reduces the navigational workload of the OOW
What is the difference between an ECS and an ECDIS?
An ECS (Electronic Chart System) is not approved and cannot be used as your primary means of navigation whereas ECDIS can be.
What is a Raster Chart?
Digital photocopy of an existing paper chart
What is the difference between an ENC and a SENC?
- ENC is the data in binary code containing the information of the displayed image
- SENC is the display of the information.
What are the 3 main displays of an ECDIS?
Base - used for initial planning only
Standard - minimum required for navigation
All - All features of the display turned on
What considerations do you make when setting the safety contour?
- Draft
- Under Keel Clearance (UKC)
- Squat
- Manoeuvrability
- How compact the contours are
- Height of tide (only when required)
What are the advantages of an ENC vector chart?
- 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
What is the S-52 standard?
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.
What is the S-57 standard?
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.
What is safety depth?
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.
What is safety contour?
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.
What is the calculation for safety depth?
Safety depth = Draught + UKC - HOT
What are the ECDIS alarms?
CDPAD
- Crossing safety contour
- Deviation from route (crossing XTE)
- Positioning system failure
- Approach to a critical point
- Different geodetic datum
What are ECDIS indications?
- Information over-scale (SCAMIN)
- Larger scale ENC available
- No ENC available
- Route planning across safety contour
- Route planning across specified area
- System test failure
What are the advantages of ECDIS?
- 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
What are the limitations of an ECDIS?
- False sense of security
- GPS could lack accuracy
- Information Overload
- Tendency to obscure view at night
- Over reliance
- Potential old survey information
What are the advantages of a RCDS?
- Global coverage
- Familiar as same as paper charts
- Fully approved
- Cheap
What are the limitations of RCDS?
- Cluttered when zoomed out
- Different scales
- Not scalable
- No anti-grounding alarms
- Not seamless, has boundaries
- Cannot be interrogated
What are some ways to check that our position displayed on ECDIS is our actual position?
- 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
What is meant by integrity monitoring?
To continuously assess the quality and reliability of the electronic chart data being displayed to ensure it meets certain standards
What are the ECDIS back-up requirements for yachts under 3000 GT?
- 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
What is CATZOC?
Category Zone of Confidence are the values that used to highlight the accuracy of data presented on charts.
What is Admiralty Vector Chart Service?
(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.
What are the inputs required for ECDIS under SOLAS?
- Emergency power source
- Gyro compass
- Speed log
- GPS receiver
- Compatible with latest IHO standards
How do you know that ECDIS is displaying the correct symbols?
- 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.
What happens if you lose your GPS on ECDIS?
ECDIS will go into DR mode and will base your position on your heading and STW
Which vessels is it mandatory to have ECDIS?
- All passenger ships over 500GT
- All cargo ships over 3000 GT
