ASA 105: Skill 13, Set and Drift, continued
13. Determine a course to steer which takes into account known current and leeway. The use of "vector diagrams" solves set and drift problems. It is back to Algebra 1 class. The table on page 58 of Eldridge 2022 is also simple and useful. Let's solve a problem graphically. This can be quickly done graphically for any angle and speed of current on your chart. The two images demonstrate that by using colored yarns to mark various elements of the problem. Image 1 Image 2 The plan is to depart Menemsha Harbor and sail to Breton Point at a projected speed of 7 knots. The Rhumb Line distance is 27.3 nm. The current for the entire trip is 060 degrees True at 1/2 knot. The dark blue yarn shows the Rhumb Line of 280 degrees True. The blue arrow at midcourse is the current direction, 060d T The red arrow is the destination R "2" Fl R 4 sec Whistle off Breton Point The green arrow is the starting point at Menemsha Harbor What is the course to steer? If we make...