Charts

Question 1

Two methods of showing survey data on paper charts

Answer 1

Old
- Source diagram indicated when and how survey was conducted. Mariner would have to deduce degree of confidence to place in information.

New
- New source diagrams use CATZOC diagrams. Gives more detail and accuracy of hydrographic data

Question 2

How survey data is presented on ENC’s

Answer 2

• Use Category zones of Confidence (CATZOC)
• Values are assigned geographical areas depending on the accuracy of data. This includes position, depth and seafloor coverage
• Presented in triangles on ENC using stars. 6 stars is most accurate and 2 two stars being least. Finally, U, survey data is un-assessed.

Question 3

Define Port Approach Guides

Answer 3

• Port scale charts with a wide range of planning information from existing charts and pubs, to help simplify passage planning and support MPX

To help answer this question imagine you are on ship off Nab Tower what information would expect to see on a chart as you transit the Southampton Pilotage

Question 4

Define Mariners Routing Guides

Answer 4

• Routing information to help Bridge teams Navigate busy shipping routes

To help answer this question imagine you are off the west coast of Brittany and want to plan a passage up the English Channel past Dover. What information would you need

Question 5

List the contents of a Routing Guide

Answer 5

• Highlights dangers
• TSS lanes
• Warnings to Nav
• Limited depths
• Dense traffic areas
• Deep channels
• Reccomended routes
• Inshore traffic zones
• Racon beacons
• Weather forecast areas
• VTS reporting points
• VTS reporting frequencies
• SAR radio frequencies
• Instructions for APEM
• Important Navigational Buoys

Question 6

What are the IHO ECDIS Standards and there meaning

Answer 6

• S-57 Transfer Standard of ENC data to ECDIS
• S-58 Validation checks performed by hydrographic offices
• S-63 Data protection, Ensures it cannot be copied, it is authentic and requires user to have license to access
  S-52 Display standards

Question 7

Define Safety Contour and its functions

Answer 7

• User select function that discriminates between safe and hazardous water
• Selects the user inputted safety contour or the next deepest contour
• Alarms when vessels crosses contour
• Uses two shades or four shades to distinguish between depths

Question 8

Define Safety depth and its functions

Answer 8

• User select function that highlights spot soundings.
• depths shallower then user input appear bold and black and depths deeper appear greyed out

Question 9

Outline limitations when in RCDCS mode

Answer 9

• Vessels must carry up to date paper charts
• Has chart boundaries (same as paper charts)
• Will not trigger automatic alarms (e.g. safety contour)
• RNC features cannot be removed, screen can become cluttered
• No look ahead function without selecting different chart
• Not possible to interrogate RNC features to gain more info
• Zooming in and out can seriously degrade quality

Question 10

Define SCAMIN

Answer 10

• A ENC function used to reduce display clutter by editing out certain details over a range of display scales.