Section 1: Terrestrial Position Fixing (Challenge Questions) Flashcards
Are Admiralty Routing charts small-scale or large-scale charts? Why is it so?
It is a small scale chart, as it include routes and distances between major ports, ocean currents, ice limits, load lines and wind roses. They also contain expected meteorological and oceanographic conditions for each ocean and each month of the year.
As a Master, what are the things you would check in the 2nd Mates passage plan?
- Passage plan is from berth to berth
- Navigational charts and publications are adequate and up-to-date.
- Distance from hazards as per Master’s Orders.
- UKC as per SMS.
- Nav warnings.
Local Wx - Contingency planning.
- Reporting details.
- Local Regulations.
- Compulsory pilotage area. (From a Master’s perspective, insurance is void and vessel is considered unseaworthy.)
- Anchorage area.
- Courses laid out on the charts.
- PFI at appropriate intervals.
- ‘NO-GO Areas’ not marked on the charts.
A Passage plan should include:
- True courses and distances.
- Methods and frequency of position fixing.
- Alter course and wheel-over positions.
- Margins of safety for each leg.
- Abort Points / Point of ‘No-Return’.
- Wrecks and hazards in proximity of intended course line.
Radar conspicuous objects (mark only the ones that are useful).
- Parallel indexing information.
- Reporting positions for Vessel Traffic Information System.
- Pilot Boarding Area.
- High density traffic areas.
- Weather assessment and monitoring.
- Static and Dynamic drafts.
- UKC.
- Air draft.
- Effect of tides and currents.
- Notes covering any useful/ relevant local information and regulatory restrictions.
Which three countries share their chart data with UKHO? Hint: They are listed in NTMs.
Australia, New Zealand and Japan.
Are US and Canadian charts similar to British Admiralty (BA) or Australian (AUS) charts? If not, what are the differences? Hint: If you haven’t seen these charts during your sea career, you can find this information by researching online.
- Measurement units.
- Color theme.
You have a newly joined deck cadet who is to undergo training under your supervision onboard. Describe how you would ensure that the cadet is properly trained in position fixing.
Ensure the cadet knows the proper procedure which can be found in,
- Bridge Procedure Manual
- SMS
- Mariner’s Handbook
- NP5011 and NP5012
- Master’s Standing Orders
- Guide to Port Entry
- Either calculate Gyro or Compass Error.
- Verify with the GPS.
- Passage planning documents
- Routeing Charts.
Refer to a coastal chart such as AUS173 shown in the reading content above and identify all the information which can be obtained from the chart. Also, see if you can identify all the symbols. Which Nautical Publications (NP) (hard copy and digital) can be used to identify the paper chart / ENC symbols?
K Rocks, Wrecks, Obstructions, Aquaculture
Paper Chart - NP5011
ECDIS - NP5012
Green sections are drying heights when low tide.
Does Australia have NAVTEX?
Australia uses the Inmarsat’s SafetyNET EGC as the primary means of promulgating MSI.
What are the publications needed for Passage Planning?
- ALRS
- ALL
- ATT
- ASD
- Ocean Passages of the World
- Met Info (ALRS Vol.3, Wx fax timing)
During low tide the land extends, how would you check the size of the land?
What is the quickest method to see if the buoy is in the right position?
Radar overlay on the ECDIS to check.
As per which regulation does it mention that compass needs adjustments.
As per Marine Order 21, Safety and Emergency Arrangements, if the deviaiton is more than 5 degrees the compass needs to be adjusted.
The deviaiton should be calculated once per watch. (NSCV Part C Sub-section 7c).
After a major alteration.
How to practically use a gnomonic chart to navigate from UK to US passing the North Atlantic?
Insert waypoints at certain lat and long at certain intervals. This method saves miles.
What are the limitations of GPS?
Intentional:
Jamming
Hacking
Unintentional:
Power Failure
Wx related damage
What are the publications needed in Australia?
- AHP11, Australian National Tide Tables or AusTides (AHP114), Printed Only (AusTides CD-ROM).
- AHP18 (Australian Fortnightly NTM), AHS download.
- AHP20 (Seafarer’s Handbook for Australian Waters), Printed Only.
- AHP24 (Australian Chart and Publication Maintenance Handbook), AHS Dowload. (Shows how to report errors.)
- Maritime Gazetteer of Australia (MGA)
Advantages and limitations of a Mercator chart.
Advantages:
- preserves angles and therefore also shapes of small objects.
- close to the equator, the distortion of lengths and areas is insignificant.
- a straight line on the map corresponds with a constant compass direction.
- simple navigation
- meridians and parallels make a rectangular grid on the map
Limitations:
- Does not preserve lengths or areas further from the equator. (Polar regions are not covered.)
- the smallest distance on the globe is not realized by a straight line on the map.
- not suitable for teaching geography and in political maps.
(this projection distorts areas and sizes of states and continents, for example Africa and Greenland seem to be the same size)
- line with the shortest distance is not obvious from the map.
- Different datum used.
Advantages and limitations of a Gnomonic chart.
Advantages:
It projects great circles as straight lines, regardless of the aspect. Able to plot intermediate waypoints. The projection is not conformal nor is it equal-area. This is a useful projection for navigation because great circles highlight routes with the shortest distance.
Limitations:
The gnomonic projection is limited by its perspective point and cannot project a line that is 90° or more from the center point. This means that the equatorial aspect cannot project the poles, and the polar aspects cannot project the equator. This projection should not be used to map more than one-third of the planet.
What are the different zones of confidence (CATZOC)
