{"id":368,"date":"2020-10-22T14:19:30","date_gmt":"2020-10-22T14:19:30","guid":{"rendered":"https:\/\/maritimesa.org\/nautical-science-grade-11\/?p=368"},"modified":"2021-01-07T08:15:45","modified_gmt":"2021-01-07T08:15:45","slug":"finding-the-set-rate-and-drift-of-a-current","status":"publish","type":"post","link":"https:\/\/maritimesa.org\/nautical-science-grade-11\/2020\/10\/22\/finding-the-set-rate-and-drift-of-a-current\/","title":{"rendered":"Finding the set, rate and drift of a current"},"content":{"rendered":"<p>The best way of demonstrating how to find the set, rate and drift of a current is by using a practical example:<\/p>\n<p><strong>Problem:<\/strong><br \/>\nFrom an observed position at 1200 a vessel steers 110\u00b0 (T) at 12 knots. At 1330 another fix is obtained. Determine the set rate and drift of the current..<\/p>\n<p><strong>Solution:<\/strong><\/p>\n<ol>\n<li>Plot the 1200 position on the chart.<\/li>\n<li>Lay off a course of 110\u00b0 (T) from the 1200 position.<\/li>\n<li>Calculate the distance steamed between 1200 and 1330.<\/li>\n<li>Measure this distance from the 1200 position and plot the 1330 DR position.<\/li>\n<li>Plot the actual 1330 position on the chart.<\/li>\n<li>Join the 1330 DR position with the 1330 fix on the chart.<\/li>\n<li>The set of the current is the direction from the DR position to the actual 1330 position.<\/li>\n<li>The drift is the distance between the DR and the actual 1330 position.<\/li>\n<li>The rate is the drift divided by the time interval.<\/li>\n<\/ol>\n<div id=\"attachment_578\" style=\"width: 910px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-578\" src=\"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-content\/uploads\/sites\/6\/2021\/01\/11.1.8.5_fig_1_r.jpg\" alt=\"\" width=\"900\" height=\"501\" class=\"size-full wp-image-578\" srcset=\"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-content\/uploads\/sites\/6\/2021\/01\/11.1.8.5_fig_1_r.jpg 900w, https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-content\/uploads\/sites\/6\/2021\/01\/11.1.8.5_fig_1_r-300x167.jpg 300w, https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-content\/uploads\/sites\/6\/2021\/01\/11.1.8.5_fig_1_r-768x428.jpg 768w, https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-content\/uploads\/sites\/6\/2021\/01\/11.1.8.5_fig_1_r-260x146.jpg 260w, https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-content\/uploads\/sites\/6\/2021\/01\/11.1.8.5_fig_1_r-50x28.jpg 50w, https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-content\/uploads\/sites\/6\/2021\/01\/11.1.8.5_fig_1_r-135x75.jpg 135w\" sizes=\"(max-width: 900px) 100vw, 900px\" \/><p id=\"caption-attachment-578\" class=\"wp-caption-text\">A line joining the A and C positions will be the &#8216;course made good&#8217; during the time interval.<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"<p>The best way of demonstrating how to find the set, rate and drift of a current is by using a practical example: Problem: From an observed position at 1200 a vessel steers 110\u00b0 (T) at 12 knots. At 1330 another fix is obtained. Determine the set rate and drift of [&hellip;]<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,64,69],"tags":[],"class_list":["post-368","post","type-post","status-publish","format-standard","hentry","category-11-1-navigation","category-11-1-8-currents-and-tidal-streams","category-11-1-8-5-finding-the-set-rate-and-drift-of-a-current"],"_links":{"self":[{"href":"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-json\/wp\/v2\/posts\/368"}],"collection":[{"href":"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-json\/wp\/v2\/comments?post=368"}],"version-history":[{"count":4,"href":"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-json\/wp\/v2\/posts\/368\/revisions"}],"predecessor-version":[{"id":587,"href":"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-json\/wp\/v2\/posts\/368\/revisions\/587"}],"wp:attachment":[{"href":"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-json\/wp\/v2\/media?parent=368"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-json\/wp\/v2\/categories?post=368"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/maritimesa.org\/nautical-science-grade-11\/wp-json\/wp\/v2\/tags?post=368"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}