NAV 6 Prelim Flashcards by Ahron Gabriel

– stands for Electronic Chart Display and Information System
– a computer-based navigation system that displays electronic nautical charts and provides
essential navigational information
– essentially a digital navigation tool used on ships to replace traditional paper charts

ECDIS

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Advantages of ECDIS over Paper Charts

● Accuracy
● Efficiency
● Additional Information
● Safety

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Electronic charts are updated more frequently and are generally more accurate than paper charts

Accuracy

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Route planning navigation are faster and easier with ECDIS

Efficiency

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ECDIS can display information from various sources, such as weather data, tidal information, and AIS (Automatic Identification System) data

Additional Information

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ECDIS offers enhanced safety features like collision avoidance and grounding alarms

Safety

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– digital representations of nautical charts, standardized in content, structure, and format
– also known as vector charts
– datasets to support all types of nautical navigation
– large commercial vessels originally adopted them for the sake of SOLAS compliance, efficiency, and safety benefits

Electronic Navigational Charts (ENCs)

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describe the characteristics of an object

Attributes

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define how objects are connected

Relationships

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Key Data Layers

● Bathymetry Layer
● Topography Layer
● Navigation Aids Layer
● Hydrography Layer
● Obstacles Layer
● Other Layers

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– depicts underwater depths, contours, and seabed topography
– includes sounding data, depth curves, and seabed features like canyons and ridges

Bathymetry Layer

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represents land features, including coastlines, islands, elevations, and terrain characteristics

Topography Layer

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displays aids to navigation such as buoys, lighthouses, beacons, and radio navigation systems

Navigation Aids Layer

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provides information about water-related features like currents, tides, and water
depths near the coast

Hydrography Layer

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indicates hazards to navigation, including wrecks, obstructions, and underwater
dangers

Obstacles Layer

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additional layers may include maritime boundaries, port facilities, and environmental information

Other Layers

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Sources of Data Inaccuracy

● Survey Methods
● Generalization
● Data Age
● Human Error

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Variations in survey techniques and equipment can affect data precision

Survey Methods

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Simplifying complex features for chart representation can introduce errors

Generalization

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Changes in seabed topography, coastline, and navigation aids over time can render data outdated

Data Age

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Mistakes in data collection, processing, or encoding can lead to inaccuracies

Human Error

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Mitigating Data Risks

● ENC Quality Control
● User Verification
● Safety Margin
● Regular Updates

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Hydrographic offices implement rigorous quality control measures to ensure data accuracy

ENC Quality Control

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Mariners should always cross-reference ENC data with other available information (radar, visual observations, nautical publications)

User Verification

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Maintain a safe distance from charted dangers and exercise caution in areas with uncertain data

Safety Margin

Stay informed about ENC updates and corrections to minimize data discrepancies

Regular Updates

– the algorithms that determine which chart information is displayed at specific scales – essential for preventing chart clutter and ensuring optimal readability – based on the S-57 ENC standard and IHO Presentation Library

Presentation Rules

Types of Presentation Rules

● Scale-Dependent Rules ● User-Defined Rules ● Priority-Based Rules

automatically adjust chart display based on the current scale

Scale-Dependent Rules

allow mariners to customize chart display based on their preferences and operational requirements

User-Defined Rules

assign priorities to different chart objects, ensuring critical information is always displayed

Priority-Based Rules

Display Options & Other Data Chart Formats

● Overlay Function ● Split Screen Mode ● Zoom Function ● Rotation Function ● User-Defined Views

combine multiple data layers for comprehensive situational awareness

Overlay Function

view different chart areas or data types simultaneously

Split Screen Mode

adjust chart scale to focus on specific areas of interest

Zoom Function

align the chart with the vessel’s heading for enhanced orientation

Rotation Function

create custom display layouts for specific tasks or preferences

User-Defined Views

create custom display layouts for specific tasks or preferences

User-Defined Views

– simply an electronic image of a paper chart – digitized by scanning the paper chart and converting each line to a raster picture element or “pixel” – beyond geo-referencing (positioning the scanned chart so that it appears in the right location with correct x and y coordinates), there is no intelligence or extra data in the image

Raster Charts

“smart charts”, which means the user can click on different features, such as a light or buoy, to retrieve additional information not available in paper or raster charts

Vector Charts

– a directive adopted by the Maritime Safety Committee (MSC) of the IMO, outlining the performance standards for ECDIS – these standards ensure that all ECDIS equipment meets specific requirements for functionality, accuracy, and reliability, providing a consistent framework for maritime navigation systems worldwide

Resolution MSC.530(106)

ECDIS must be capable of displaying Electronic Navigational Charts (ENCs) and, where necessary, Raster Navigational Charts (RNCs). The system should present chart data clearly and accurately, facilitating effective route planning and monitoring.

Chart Display Requirements

To ensure navigational safety, ECDIS must support the automatic updating of chart data. This includes integrating updates from authorized hydrographic offices, ensuring that navigators have the most current information at their fingertips.

Automatic Updating

ECDIS must provide robust tools for route planning and monitoring. This includes functionalities for setting and modifying routes, detecting and alerting to potential hazards, and continuously monitoring the vessel's position relative to the planned route.

Route Planning & Monitoring

The system should offer an intuitive user interface, making it easy for navigators to access and interpret information. Additionally, ECDIS must have a comprehensive alert system to warn of navigational dangers, system malfunctions, or deviations from planned routes.

User Interface Alerts

To enhance reliability, ECDIS must be supported by adequate backup arrangements. This ensures that, in the event of a system failure, navigators can continue to access essential chart information and maintain situational awareness.

Backup Arrangements

ECDIS should have capabilities for recording and storing navigational data, which can be vital for post-voyage analysis and in the event of an incident investigation.

Data Recording

Benefits of Complying with RESOLUTION MSC.530(106)

● Enhanced Safety ● Regulatory Compliance ● Operational Efficiency ● Competitive Advantage

Complying with MSC.530(106) ensures that ships are equipped with the most advanced navigational technology, significantly enhancing maritime safety

Enhanced Safety

Meeting the IMO’s performance standards is mandatory for SOLAS (Safety of Life at Sea) vessels

Regulatory Compliance

Advanced ECDIS systems facilitate efficient route planning and navigation, leading to optimized fuel consumption and reduced operational costs. The ability to update charts automatically and access real-time navigational data further streamlines operations.

Operational Efficiency

Vessels equipped with ECDIS that meet the latest standards are more attractive to charterers and clients. Demonstrating a commitment to safety and compliance can provide a competitive edge in the maritime industry.

Competitive Advantage

Dangers of Over-Reliance on an ECDIS to the Safety of Navigation

● Loss of Situational Awareness ● System Failures ● Data Inaccuracies ● Human Error

Focusing solely on the screen can hinder visual lookout

Loss of Situational Awareness

Equipment malfunctions can lead to critical information loss

System Failures

Outdated or incorrect chart data can result in misjudgment

Data Inaccuracies

Misinterpretation of ECDIS information can lead to mistakes

Human Error

Main Formats in ECDIS

● Vector Charts ● Raster Charts

Display Modes in ECDIS

Base Display Standard Display All Other Display

permanently retained on the ECDIS display

Base Display

Base Display consists of

○ Coastline (high water) ○ Own ship's safety contour, to be selected by the mariner ○ Indication of isolated underwater dangers at depths of less than the safety contour which lie within the safe waters defined by the safety contour ○ Indication of isolated dangers which lie within the safe waters defined by the safety contour such as : bridges, overhead wires, etc., including buoys and beacons, whether these are being used as aids to navigation ○ Traffic routeing systems ○ Scale, range, orientation and display mode ○ Units of depth and height

to be displayed when the chart is first displayed by ECDIS

Standard Display

Standard Display consists of

○ Display Base ○ Drying line ○ Indication of fixed and floating aids to navigation ○ Boundaries of fairways, channels, etc. ○ Visual and radar conspicuous feature ○ Prohibited and restricted areas ○ Chart scale boundaries ○ Indication of cautionary notes

all other information, displayed individually on demand

All Other Display

Elements in Route Planning & Monitoring

○ planned route lines ○ waypoints ○ cross-track error limits ○ and safety corridors

Elements in Weather & Environmental Data

○ wind direction & speed ○ wave height ○ currents ○ other meteorological & oceanographic data

Elements in User Charts & Annotations

○ user-defined symbols ○ text annotations ○ custom areas or lines

Elements in Overlays

○ radar images ○ AIS targets ○ safety zones ○ other data overlays

Chart Orientations

● North Up ● Course Up ● Head Up

– chart is oriented with true north at the top of the display – the traditional orientation used on paper charts – often preferred for general navigation and planning

North Up

– chart is oriented with the ship’s intended course at the top of the display – useful when following a planned route, as it aligns the chart with the course line, helping mariners to stay on track

Course Up

– chart is oriented with the ship's current heading at the top of the display – often used in close quarters, like in harbors or when maneuvering in confined waters, where the mariner needs to quickly interpret what lies ahead of the vessel

Head Up

– the scale according to which the chart information meets the IHO requirements for chart accuracy – established by the producing Hydrographic Office and encoded in the ENC – in ECDIS, this scale is critical because it defines the accuracy and detail of the chart data – the scale at which the chart data was originally created or digitized

Compilation Scale

refers to the categorization of electronic navigational charts (ENCs) based on their scale and intended use

Navigational Purpose/Band in ECDIS

Basic Steps of Route Planning (accd. to ppt)

1. Preparation 2. Planning the Route 3. Optimization 4. Safety Check 5. Finalizing the Route 6. Review & Update 7. Documentation

Basic Steps of Route Planning (accd. to sir)

1. Appraisal 2. Planning 3. Execution 4. Monitoring

Common Alarms in ECDIS

● Cross Track Error (XTE) Alarm ● Proximity to Hazards Alarm ● Anchor Drag Alarm ● Safety Contour Alarm ● AIS Target Closest Point of Approach (CPA) Alarm

alerts the crew when the vessel deviates beyond a set distance from the planned track

Cross Track Error (XTE) Alarm

ensures the vessel remains within a safe corridor, minimizing the risk of encountering hazards

Cross Track Error (XTE) Alarm

triggers when the vessel is getting too close to identified hazards such as shallow waters, rocks, or wrecks

Proximity to Hazards Alarm

provides early warning to avoid groundings or collisions with underwater obstacles

Proximity to Hazards Alarm

activates if the vessel moves outside a predefined radius while at anchor

Anchor Drag Alarm

helps prevent unintended drifting which could lead to collisions or groundings

Anchor Drag Alarm

warns when the vessel is crossing a safety contour that indicates a change in depth

Safety Contour Alarm

prevents the vessel from entering areas that are too shallow, reducing the risk of grounding

Safety Contour Alarm

triggers when another vessel is predicted to come within a certain distance

AIS Target Closest Point of Approach (CPA) Alarm

provides time to take evasive action to prevent collisions

AIS Target Closest Point of Approach (CPA) Alarm

the most important parameter of all the safety settings for the display of unsafe water areas, detecting isolated dangers and triggering anti-grounding alarms

Safety Contour

an outline which marks the division between safe and unsafe waters

Safety Contour

its sole purpose is to portray spot soundings either in gray for deeper depths or black for shallower depths compared to the safety depth value entered by the navigating officer thereby highlighting the potentially safe and unsafe areas

Safety Depth

What is the default safety contour on ECDIS as per IMO Resolution MSC.530(106) Performance Standards?

30 m

NAV 6 Prelim Flashcards

(91 cards)