Which option describes the Computed method in Set and Drift calculations?

• A. Real time updates by comparing ship heading and speed with course and SOG
• B. Set and drift calculated at fixed intervals
• C. Both Computed and Ordered methods are the same
• D. Neither method uses real-time heading data

Answer: (A)

The Computed method relies on real-time observation of the vessel’s motion to determine how the water is moving around it. It continually updates set and drift by analyzing how the ship is actually moving—its heading and speed—compared with the course you intend and the resulting speed over ground. When you compare the heading and speed (through the water) to the course and speed over ground, any difference reveals the current’s push on the vessel. From those differences you infer the current’s direction (set) and its speed (drift). This live, ongoing calculation is what makes the Computed method responsive to changing conditions.

This is why it’s the best description: it emphasizes real-time updates using the ship’s current motion data, rather than relying on fixed-interval calculations or on non-real-time data.