{"id":834,"date":"2021-12-01T20:21:03","date_gmt":"2021-12-01T19:21:03","guid":{"rendered":"https:\/\/anclademia.com\/?p=834"},"modified":"2022-06-08T15:23:35","modified_gmt":"2022-06-08T14:23:35","slug":"directions","status":"publish","type":"post","link":"https:\/\/anclademia.com\/en\/blog\/rumbos\/","title":{"rendered":"Definition of headings"},"content":{"rendered":"<h2 class=\"wp-block-heading\">True, Magnetic and Needle Course: Definitions<\/h2>\n\n\n\n<p>The headings are defined in&nbsp;<strong><em>function of the meridian taken as origin&nbsp;<\/em><\/strong>(true, magnetic or needle) and the bow-stern line of the vessel.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong><em>TRUE course&nbsp;<\/em>(Rv)<\/strong>: he&nbsp;<strong><em>angle formed by the true meridian of the place and the bow-stern line<\/em><\/strong>.<\/li><li><strong><em>MAGNETIC course&nbsp;<\/em>(Rm):&nbsp;<\/strong>he&nbsp;<strong><em>angle formed by the magnetic meridian of the place and the bow-stern line<\/em><\/strong>.<\/li><li><strong><em>NEEDLE course&nbsp;<\/em>(Ra)<\/strong>: he&nbsp;<strong><em>angle formed by the needle meridian&nbsp;<\/em><\/strong>(determined by the orientation of the needle and differs from the magnetic due to the magnetic materials of the ship)&nbsp;<strong><em>and bow stern line<\/em><\/strong>.<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Relationship between them<\/h2>\n\n\n\n<p>If we look at Figure 9.11, we can deduce that: Rv = Ra + \u0394 + dm, and since Ct = dm + \u0394.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>Rv = Ra + Ct<\/strong><\/li><li><strong>Ra = Rv \u2013 Ct<\/strong><\/li><\/ul>\n\n\n\n<p>From the same figure it is also easy to deduce that:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>Rm = Ra + \u0394 Rm = Rv \u2013 dm<\/strong><\/li><\/ul>\n\n\n\n<div class=\"btn-groc-cta\"><br><strong>Are you interested in: <\/strong><a href=\"https:\/\/anclademia.com\/en\/blog\/nautical-needle\/\"> Nautical needle <\/a><\/div>\n\n\n\n<h2 class=\"wp-block-heading\">Ways to measure quadrantal and circular heading<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><strong><em>Circulars<\/em>:&nbsp;<\/strong>from&nbsp;<strong><em>0o to 360o&nbsp;<\/em><\/strong>and clockwise. Its value is always positive.<\/li><li><strong><em>Quadrantals (or quadrants)<\/em>:&nbsp;<\/strong>dividing the circumference into&nbsp;<strong><em>four quadrants<\/em><\/strong>.<\/li><\/ul>\n\n\n\n<p>To avoid confusion the directions must be said or&nbsp;<strong><em>state by numbers<\/em><\/strong>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">From quadrantal value to circular<\/h2>\n\n\n\n<p>Of&nbsp;<strong><em>degrees to quadrantals&nbsp;<\/em><\/strong>either&nbsp;<strong>\u201c<em>quadrants<\/em>\u201d&nbsp;<\/strong>to&nbsp;<strong>circular degrees:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Between&nbsp;<strong><em>000-090&nbsp;<\/em><\/strong>\u2013 belong to the 1st quadrant (NE) and correspond to the&nbsp;<strong><em>same number of degrees<\/em><\/strong><\/li><li>Between&nbsp;<strong><em>090-180&nbsp;<\/em><\/strong>\u2013 belong to the 2nd quadrant (SE) \u2013 Se&nbsp;<strong><em>subtract from 180o<\/em><\/strong><\/li><li>Between&nbsp;<strong><em>180-270&nbsp;<\/em><\/strong>\u2013 belong to the 3rd quadrant (SW) \u2013 They&nbsp;<strong><em>180o remains<\/em><\/strong><\/li><li>Between&nbsp;<strong><em>270-360&nbsp;<\/em><\/strong>\u2013 belong to the 4th quadrant (NW) \u2013 They&nbsp;<strong><em>subtract from 360o<\/em><\/strong><\/li><\/ul>\n\n\n\n<p><strong><em>Examples:<\/em><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong><em>N45oE = 045o&nbsp;<\/em><\/strong><em>(First quadrant).<\/em><\/li><li><strong><em>S10oE =&nbsp;<\/em><\/strong><em>180o \u2013 45o =&nbsp;<\/em><strong><em>135th&nbsp;<\/em><\/strong><em>(Second quadrant)<\/em>.<\/li><li><strong><em>S10oW =&nbsp;<\/em><\/strong><em>180o + 45o =&nbsp;<\/em><strong><em>225th&nbsp;<\/em><\/strong><em>(Third quadrant)<\/em><\/li><li><strong><em>N45oW =&nbsp;<\/em><\/strong><em>360o \u2013 45o =&nbsp;<\/em><strong><em>315th&nbsp;<\/em><\/strong><em>(Fourth quadrant)<\/em>.<\/li><\/ul>","protected":false},"excerpt":{"rendered":"<p>True, Magnetic and Needle Course: Definitions Courses are defined in terms of the meridian taken as the origin (true, magnetic or needle) and the bow-stern line of the vessel. TRUE Course (Rv): The angle formed by the true meridian of the place and the bow-stern line. MAGNETIC Course (Rm): The angle formed by the magnetic meridian of the place and the bow-stern line. <a title=\"Definition of headings\" class=\"read-more\" href=\"https:\/\/anclademia.com\/en\/blog\/rumbos\/\" aria-label=\"Read more about Defining Courses\">Read more<\/a><\/p>","protected":false},"author":1,"featured_media":14129,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[69],"tags":[],"class_list":["post-834","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-navegacion"],"jetpack_featured_media_url":"https:\/\/anclademia.com\/wp-content\/uploads\/2021\/12\/Rumbo.jpg","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/anclademia.com\/en\/wp-json\/wp\/v2\/posts\/834","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/anclademia.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/anclademia.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/anclademia.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/anclademia.com\/en\/wp-json\/wp\/v2\/comments?post=834"}],"version-history":[{"count":0,"href":"https:\/\/anclademia.com\/en\/wp-json\/wp\/v2\/posts\/834\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/anclademia.com\/en\/wp-json\/wp\/v2\/media\/14129"}],"wp:attachment":[{"href":"https:\/\/anclademia.com\/en\/wp-json\/wp\/v2\/media?parent=834"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/anclademia.com\/en\/wp-json\/wp\/v2\/categories?post=834"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/anclademia.com\/en\/wp-json\/wp\/v2\/tags?post=834"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}