1. What is the Distance Between Ports Calculation?

The distance between two sea ports is calculated using the spherical law of cosines formula, which provides the great-circle distance (shortest distance over the earth's surface) between two points given their latitude and longitude coordinates.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• \( lat1, lat2 \) — Latitude of ports 1 and 2 (in degrees)
• \( lon1, lon2 \) — Longitude of ports 1 and 2 (in degrees)
• 3440 — Approximate radius of the Earth in nautical miles

Explanation: The formula calculates the central angle between the two points and then multiplies by the Earth's radius to get the distance.

3. Importance of Distance Calculation

Details: Accurate distance calculation between ports is essential for voyage planning, fuel estimation, and navigation in maritime operations.

4. Using the Calculator

Tips: Enter latitude and longitude coordinates in decimal degrees (positive for North/East, negative for South/West). The calculator will compute the great-circle distance in nautical miles.

5. Frequently Asked Questions (FAQ)

Q1: What is a nautical mile?
A: A nautical mile is approximately 1.852 kilometers or 1.151 statute miles, based on the Earth's circumference.

Q2: How accurate is this calculation?
A: This provides a good approximation, but actual distances may vary slightly due to Earth's ellipsoidal shape.

Q3: Can I use this for airports as well?
A: Yes, the formula works for any two points on Earth when given their latitude and longitude.

Q4: What's the difference between great-circle and rhumb line distance?
A: Great-circle is the shortest path, while rhumb line maintains constant bearing (longer but easier to navigate).

Q5: Why 3440 for Earth's radius?
A: The mean radius of Earth is approximately 3440 nautical miles (6371 km converted to nautical miles).