Underway - Pacific Crossing Notes: A Sailor's Guide to the Coconut Milk Run - page 127

Putting It All Together
For a complete example, let's go back to that June evening in Fiji: an overnight passage,
the sun setting to the west, and a mostly cloudless sky. Beam reaching on a course of 145°
at evening twilight, we were lucky to have Venus available for a sight. Figure 5, A Sample
Sight shows the five sights we took of Venus, sorted by intercept.
Figure 5: A sample sight
Our second sight landed on the median position with an intercept of 17.2T. Since we had a
GPS position to later check our fix, we could also calculate the theoretically correct inter-
cept of 16.8T. This made our median sight 0.4' too high but significantly better than sights
1, 3, and 4. As it turned out, sight number 5 was even closer to the true value, although we
would have had no way of knowing that without peeking at the GPS. Our objective here is