Cara Menentukan Posisi Kapal Dengan Baringan 4 Surat

Summary

This video explains the concept of 'Baringan Empat Surat' (Four Point Bearing), a technique used to determine a ship's true position by calculating the relative bearing between the ship and a land object. The process involves using mathematical principles and geometry, such as 45° triangles, to compute distances and bearings. The tutorial walks through a practical example of navigating a ship using speed, time, and relative bearings, helping viewers understand how to calculate the ship's true heading and position on a nautical chart. The video provides clear, step-by-step instructions for maritime navigation.

Takeaways

• 😀 Baringan Empat Surat (45° bearing) is a technique used to determine a ship's true position by measuring the angle between the ship’s bow and a fixed land object.
• 😀 The term 'Baringan Empat Surat' comes from the fact that 45° equals four compass points, with each point representing 11.25°.
• 😀 The 45° relative bearing forms the basis for the navigation triangle, where a 45° angle with a 90° right angle triangle gives equal distances between the points.
• 😀 The method uses geometry to estimate the ship's location, with distances equal between the ship and the land object when plotted on a map.
• 😀 To solve navigation problems, one must first calculate the true heading of the ship by factoring in compass variation and deviation.
• 😀 True heading is calculated by adding the variation (East or West) and deviation (East or West) to the compass heading.
• 😀 Once the true heading is determined, it is drawn on a nautical chart to indicate the ship’s course.
• 😀 After setting the true heading on the chart, the 45° relative bearing is drawn to represent the first bearing from the ship to the object.
• 😀 The relative bearing is transferred to the position of the land object on the map to locate the ship’s position at the given time.
• 😀 By calculating the distance covered by the ship in a given time (using speed and time), one can estimate the position of the ship on the map during the second bearing measurement.
• 😀 The ship’s true position is derived by transferring the distance from the first bearing to the second bearing on the map, providing the ship's actual location.

Q & A

What is the technique of 'baringan empat surat' or 'baringan 45'?

The technique of 'baringan empat surat' (also known as 'baringan 45') is used to determine the true position of a ship by using a 45° bearing relative to a land object. It involves measuring the angle formed between the ship's true heading and the line of bearing to the land object.

Why is 'baringan 45' referred to as 'four letters bearing'?

It is called 'four letters bearing' because the bearing of 45° corresponds to four 'letters' of a compass, where each letter or point on a compass represents 11.25°, so 45° is 4 times 11.25°.

What is the significance of the 45° angle in the method?

The 45° angle plays a crucial role in simplifying the math behind the calculation. It is part of a right triangle (45°-45°-90°) where the sides opposite the angles are of equal length, helping to determine the true distance between the ship and the land object.

How does the triangle geometry help in determining the ship’s position?

The triangle geometry (specifically a 45°-45°-90° triangle) shows that if the angle between the ship’s heading and the line of bearing is 45°, the distance from the ship to the land object is equal to the distance along the bearing path. This helps in calculating the true position of the ship.

What steps should be followed to determine the ship's true heading?

To determine the true heading, you need to add the deviation and variation to the ship's compass heading. For example, if the compass heading is 025°, the variation is 2° East, and the deviation is 3° East, the true heading would be 030°.

What is the process of plotting the ship’s heading on a nautical chart?

To plot the ship's heading, draw a line from the compass rose at 030° on the nautical chart. Then, transfer the heading to any point on the chart using a straightedge or parallel rulers to mark the ship's course.

How is the relative bearing of 45° used in this method?

The 45° relative bearing is created by drawing a line from the ship's true heading at 030° and then adding 45° to it, which results in a bearing of 075°. This bearing helps to identify the relative position of the ship in relation to the land object.

How do you determine the position of the ship at 06:00 using this method?

At 06:00, you calculate the intersection of the relative bearing line (75°) with the true heading line (30°). The point where these lines intersect on the chart indicates the ship's position at that time.

What is the role of time and speed in determining the ship’s location?

The time and speed are used to calculate the distance the ship travels between two bearing measurements. By multiplying the ship’s speed (in knots) by the time difference (in hours), you can calculate the distance traveled, which helps refine the position on the chart.

How is the final position of the ship determined on the nautical chart?

The final position of the ship is determined by measuring the distance traveled (2.5 miles, calculated from speed and time), and then transferring this distance onto the nautical chart. The point where the distance intersects with the second relative bearing line indicates the ship's true position.