ECDIS Safety depth settings

Summary

This script from the Active Awareness Series discusses the critical role of chart depth settings in Electronic Chart Display and Information Systems (ECDIS) for safe navigation, especially in areas with shallow waters. It explains the importance of setting contours for shallow, safety, and deep waters, and how ECDIS displays these based on user input and available data. The dialogue between the captain and third mate covers the visual representation of different water depths using color coding in two and four color displays, emphasizing the significance of safety contours and the navigational dangers they indicate. The script also touches on the practical aspects of navigating near hazards and the use of ECDIS settings to ensure safe passage.

Takeaways

• 🌊 **Importance of Chart Depth Settings**: Chart depth settings are crucial for grounding prevention and safe navigation.
• 📊 **Understanding Contours**: Contours are lines on a chart that join equal depths, and they help in visualizing underwater terrain.
• 🛳️ **Master's Role in Setting Values**: The ship's master decides the chart depth settings based on ship management guidelines.
• 🔍 **ACTUS Display of Contours**: The Automatic Chart and Tabular Information System (ACTUS) displays contours based on input values or the next higher available contour.
• 🚫 **Shallow Contour Significance**: Shallow contours indicate high grounding risk areas that vessels should avoid.
• 🔳 **Safety Contour and Navigable Waters**: Safety contours separate navigable water depths from those that are unsafe, with specific color codes indicating different depths.
• ⚠️ **Safety Contour Alarms**: ACTUS systems can be set to alarm if a vessel is on course to cross the safety contour.
• 📍 **Isolated Danger Mark Symbols**: These symbols identify navigational dangers with safe passing depths less than or equal to the safety contour setting.
• 🌈 **Color Display Options**: ACTUS offers two color settings (two-color and four-color) to represent different depth areas for better navigation.
• 🌌 **Two Color Display for Simplicity**: The two-color display is preferred in shallow waters and during night navigation for its simplicity.
• 📚 **Knowledge Refreshment**: The discussion helps in refreshing knowledge about chart depth settings which is essential for safe navigation.

Q & A

What is the importance of chart depth settings in navigation?

Chart depth settings are crucial for organizing the display of safe depths and unsafe steps, which helps in grounding prevention and safe navigation.

What does 'ECTIS chart depth settings' refer to?

ECTIS chart depth settings refer to the user-input values for shallow contour, safety contour, safety depth, and deep contour in a navigation system.

How does the ship's master decide the values for chart depth settings?

The ship's master decides the values for chart depth settings based on the ship manager's guidelines.

What is the role of the ENC in displaying depth contours?

The ENC (Electronic Navigational Chart) is programmed to display depth contours equal to the input values or the next higher available contour if the exact input value is not available.

What is the significance of the safety contour in navigation?

The safety contour acts as a separation line between navigable water depths and depths less than the safety depth, helping to avoid areas of high grounding risk.

What does the color blue signify on the chart depth settings?

In the four-color display, blue color signifies areas of high grounding risk with depths less than the shallow contour, where the vessel should never enter.

How are depths that are equal to and lesser than the safety depth displayed?

Depths equal to and lesser than the safety depth are shown in black bold fonts, indicating that the vessel must not plan passage over these areas.

What is the purpose of the alarm set by the mariner if the vessel crosses the safety contour?

The alarm is intended to alert the mariner if the vessel is about to enter an area with depths less than the safety contour, promoting safety and avoidance of grounding.

What is the significance of the isolated danger mark symbols in relation to the safety contour?

The isolated danger mark symbols identify navigational dangers with safe passing depths less than or equal to the safety contour setting. Their display is governed by the safety contour setting.

What are the two types of color displays available in the ACTIS system?

The ACTIS system offers two color settings: two-color and four-color displays. The two-color display is simpler and preferred in shallow waters and during night navigation.

How does the two-color display differ from the four-color display in ACTIS?

In the two-color display, the light blue color from the four-color display is replaced by blue, and the gray color is replaced with white, simplifying the display for easier navigation in certain conditions.