ECDIS (Electronic Chart Display and Information System)

Question 1

What is a Vector chart?

Answer 1

(ENC – Electronic Navigational Chart) - Allows for full information, interrogation, and zoom facilities.

Question 2

What is a Raster chart?

Answer 2

(RNC – Raster Navigational Chart) - Scanned paper chart with none of the above facilities. MGN 285 – Electronic Charts Operating ECDIS in RCDS mode.

Question 3

When can ECDIS be used as a primary means of navigation?

Answer 3

As per SOLAS, Chapter V, Regulation 19:
* It may be used as a primary use of navigation as long as suitable back-ups are in place. This may be paper charts or another standalone ECDIS.

Question 4

How would you carry out ECDIS chart updates?

Answer 4

 All corrections must be recorded in NP133C, which is a folder used to hold paper records on ENC and ECDIS maintenance.
 To update, and input chart corrections on ECDIS the following steps are taken:
* Find this week’s correct updated file from the Notice to Mariners Ch8.
* Download chart correction/ update file from computer to USB.
* Insert USB to master ECDIS and transfer file.
* Check updates have been updated.
* Synchronise Master ECDIS with all Slave ECDISs.
* Check updates have been made.

Question 5

What mandatory alarms must be set on the ECDIS as per MGN 379?

Answer 5

 Crossing safety contours.
 Deviation from route.
 Mandatory input failure.
 Approach to a critical point.
 Different geodetic datum .
* (This is the difference in the exact position on Earth in comparison to other planetary bodies using geodetic coordinates).

Question 6

What indications must be set on the ECDIS as per MGN 379?

Answer 6

 Default safety contour.
 Information over scale.
 Large-scale ENC available.
 No ENC available.
 Different reference system.
 Customised display.
 Route planning across safety contour.
 Route planning across a specified area.
 Crossing a danger in route monitoring mode.
 System test failure.

Question 7

What is a Safety Contour?

Answer 7

 A contour to distinguish safe and unsafe water.
 The value entered should be the Safety Depth and the ECDIS will then use the next deepest contour (5m, 10m, 20m) as the safety contour.
 Audio and a visual alarms are generated and will sound/ show if parameters exceed or do not meet.

Question 8

What is a Safety Depth?

Answer 8

 Safety Depth = (Draft + Squat + UKC) – Height of Tide.
 This tends to be twice the vessels draft; this cannot be less than the safety contour.
 Once set up, all depths up to and including the safety depth will be shown in bold print.
 No alarm are generated.

Question 9

What is a Shallow Contour?

Answer 9

 Used to identify the shallow patches within the no-go areas/ unsafe navigational areas inside the safety contour.
 It is normally set to the next contour shallower than the safety contour.
 Gives a good visual understanding of the gradient of the seabed.

Question 10

What is a Deep Contour?

Answer 10

 This is usually set to twice the vessel’s draft, and it clearly shows the safe navigable water.

Question 11

What are the different types of shade setup on the ECDIS?

Answer 11

 There are two types of shade setups on ECDIS.
* Two shades set up:
o Unsafe Water is shown in Dark Blue and safe navigational waters are shown in White.
* Four shades set up:
o Unsafe Water is shown in Dark Blue and safe navigational waters are shown in White, however, the two-lighter blues in between help visualize the gradient of the seabed.
 Neither Shallow nor Deep contours generate an alarm, they are purely visual indicators only.

Question 13

What is Static Draft?

Answer 13

 This is the vessels draft when not making its way through the water.

Question 14

What is CATZOC?

Answer 14

(Category Zone of Confidence)
 This refers to the quality and accuracy of the depth/ soundings given.

Question 15

What are layers on the ECDIS?

Answer 15

 There are three types of layers:
o Base, Standard and All/Full.
 Base layer may be used for planning but is not enough for navigation.
 Minimum layer for navigation is Standard.
 A custom layer can be added where the officer selects certain. information to display, this is used to avoid the cluttering of information which tends to happen in the All/Full Layer.

Question 16

What is Cross Track Error (XTE)?

Answer 16

 Can be independently adjusted on the port and starboard side for each leg.
 Acts like a corridor, when checking the route, any dangers within the XTE will be alarmed. While navigating, the off-track alarm would sound if the vessel were to cross the XTE.

Question 18

How is Route Checking/ Monitoring used?

Answer 18

 Once the route has been put in place, the route should be checked using the internal checking software. This would highlight any potential dangers which should be checked.
 Once all is OK, the route monitoring section should be activated, and the parameters of the safety frame adjusted.
 As the vessel departs and proceeds on its passage, any dangers that come into the safety frame will be alarmed.

Question 19

What is included in the ECDIS Passage Planning Guide?

Answer 19

• ECDIS Rough Passage Planning Guide:
  1) Set up the layers.
  2) Set up the safety contours.
  3) Feed in the position of the waypoints.
  4) Manage the XTE.
  5) Set the speed of each leg.
  6) Set radius for each turn, wheel over point.
  7) Check the route on a 1-to-1 scale using the internal ECDIS software.
  8) Give it a name and save.
  9) Activate route monitoring.
  10) Check primary/ secondary position sensors are correct.
  11) Sort alarms:
  a. Navigational Danger (Distance).
  b. Safety contours and safety frames.
  c. Echo Sounder.
  d. DGPS (Differential Global Positioning System).
  e. Off course alarm and XTE alarm.
  f. Critical points.