NAV 6 Flashcards
What do depth contours represent in an ENC?
Lines connecting points of equal depth
Depth contours assist mariners in:
Planning safe routes based on underwater topography
How are depth contours displayed in ENGS?
Using color-coded zones
What symbol is typically used to represent tidal currents in an ENC?
Arrows showing direction and strength
Tidal current information is especially critical in:
Shallow waters and coastal navigation
What are aids to navigation (AtoN)?
Buoys, beacons, and lights that guide navigation and mark hazards
The main function of navigational aids in an ENC is to:
Mark hazards and provide positional reference points
What characteristics of navigational aids are shown in an ENC?
light patterns, colors, and ranges
Coastlines on an ENC are important for:
Coastal navigation and position referencing
Which features are included in an ENC’s coastline data?
Ports, docks, and breakwaters
How are landmarks displaved in an ENC?
As symbols representing their shape and height
What kind of data on obstructions is typically found on an ENC?
Submerged rocks, wrecks, and underwater hazards
The symbols for underwater obstructions in an ENC include:
Standardized symbols with depth information
Why is hazard information critical for mariners?
To avoid running aground or colliding with underwater objects
Traffic Separation Schemes (TSS) are designed to:
Ensure smooth traffic flow and reduce the risk of collision
Shipping routes on an ENC are represented as
Defined lanes with directional markers
In congested sea areas, why is TSS data important for navigation?
To avoid collisions and regulate ship movements
Chart datum refers to:
The reference level for depth measurements
Vertical clearances on an ENC are critical for:
Passing under bridges and overhead obstructions
The height of vertical clearances is typically measured:
Above chart datum or water level
Seabed composition data helps mariners:
Plan safe anchoring areas
Why are marine protected zones marked on ENC?
To prevent vessel entry and protect sensitive environments
How are restricted areas marked on an ENC?
Shaded zones with boundaries
Tidal data in an ENC allows mariners to:
Plan routes in shallow waters
How is tidal data integrated into an ECDIS system?
As real-time updates of water levels
Why is it important to consider tidal variations when planning a route?
To ensure safe passage through shallow areas
A vessel has a maximum static draft of 12 meters. What should the shallow contour be set at?
12 meters
If a vessels maximum draft is 10 meters, company’s UKC policy is 1.5 meters, squat is 1 meter, and the height of tide is 2 meters, what is the salety depth?
Safety Depth = Max Draft (10) + UKC(1.5) + Squat (1) - Height of Tide (2) = 10.5 meters
A vessel with a draft of 6 meters is sailing in an area where the depth is 24 meters. What would be an appropriate setting for the deep contour?
Deep Contour is usually estimated as twice or four times the vessel’s draft. Here, 24 meters is four times the draft of 6 meters.
For a vessel with a maximum draft of 9 meters, the company’s UKC requirement is 2 meters, squat is 0.8 meters, and the height of tide is 1.5 meters What is the calculated safety depth?
Safety Depth = Max Draft (9) + UKC (2) + Squat (0.8) - Height of Tide (1.5) = 10.3 meters
If the vessel’s speed is 12 knots and there is a following current of 2 knots. What is the expected SOG?
14 knots
A vessel is navigating east (090°) with a southward (180°) current. What is the most likely impact on its course?
Drift to the south
