Dead Reckoning (DR) Plotting

Chapter 5, Homework question 1 from ASA's Coastal Navigation & Piloting textbook: Plotting of a Dead Reckoning (DR) course on a navigation chart based on compass course and distance traveled during a cruise.

[@dogwalker666]

Very Interesting thank you.

[@johnw3246]

Thank you Captain Tursi for your excellent videos. I have always recorded my logs for the conditions NOW, such as GPS coordinates, barometric pressure, course, speed, wind, weather, sea state, etc. So if I recently changed course, I record the new course. Which items in the log should be for the conditions NOW, and which should be for the average conditions from the PAST since the previous log entry?

[@mdschoolofsailing]

I keep the hourly entries in the logbook as shown to maintain the regularity and discipline and to support the DR plotting. If you tack during one of the regular intervals, write a "T" into the course column and write the details of that tack into the narrative section of your logbook including time, course before tack, distance log reading at that time and new course after the tack. This allows you to plot the tack into your DR plot. Thanks for your question. I hope this helps... T

[@Apweng33]

Great video thanks! For annual variation increase is the number always added to current variation?

[@mdschoolofsailing]

The compass rose on the chart will state whether the annual change is increasing or decreasing. If its decreasing, you would subtract.