Sea Voyage Distance Calculator

Great Circle Distance Formula:

\[ Distance = 60 \times \arccos(\sin(lat1) \times \sin(lat2) + \cos(lat1) \times \cos(lat2) \times \cos(\Delta long)) \]

Latitude 1:

degrees

Latitude 2:

degrees

Longitude 1:

degrees

Longitude 2:

degrees

Distance:

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1. What is Great Circle Distance?

The Great Circle Distance is the shortest distance between two points on the surface of a sphere. For sea voyage navigation, this represents the most efficient route between two locations on Earth's surface, following the curvature of the planet.

2. How Does the Calculator Work?

The calculator uses the Great Circle Distance formula:

\[ Distance = 60 \times \arccos(\sin(lat1) \times \sin(lat2) + \cos(lat1) \times \cos(lat2) \times \cos(\Delta long)) \]

Where:

\( lat1, lat2 \) — Latitude coordinates in degrees (-90 to 90)
\( \Delta long \) — Longitude difference in degrees
60 — Nautical miles per degree of arc on Earth's surface
All trigonometric functions use radians

Explanation: The formula calculates the central angle between two points on a sphere and converts it to distance using the Earth's circumference.

3. Importance of Sea Distance Calculation

Details: Accurate sea distance calculation is crucial for voyage planning, fuel estimation, arrival time predictions, and optimal route selection in maritime navigation.

4. Using the Calculator

Tips: Enter latitude values between -90° (South) and 90° (North), longitude values between -180° (West) and 180° (East). Use decimal degrees for precise calculations.

5. Frequently Asked Questions (FAQ)

Q1: Why use nautical miles instead of kilometers?
A: Nautical miles are the standard unit in maritime and aviation navigation because they correspond to one minute of latitude, making navigation calculations more intuitive.

Q2: How accurate is the great circle distance?
A: The calculation assumes a perfect sphere. For most practical navigation purposes, it's sufficiently accurate, though Earth is slightly ellipsoidal.

Q3: Can I use this for air travel distance?
A: Yes, the same principle applies to air navigation as both follow great circle routes for efficiency.

Q4: What's the difference from rhumb line distance?
A: Rhumb line maintains constant bearing, while great circle is the shortest path. Great circle is shorter but requires constant course adjustments.

Q5: How do I convert to kilometers or miles?
A: 1 nautical mile = 1.852 kilometers = 1.15078 statute miles. Multiply the result by these conversion factors.