The following example is used to explain the procedure to follow:

Problem:
From an observed position at 1200 a vessel steers 110° (T) at 10 knots. The current is setting 350° (T) at 2 knots. Determine the estimated position for 1330.

Solution:

1. Plot the true course from the 1200 position.
2. Plot the DR position for 1330.
3. Calculate the drift for the time interval (2 x 1½)miles. This will constitute the current vector at 1330.
4. Draw the current vector from the DR position.
5. The EP will be at the end of the current vector.
6. Plot the EP.