{"id":47900,"date":"2026-01-15T22:20:26","date_gmt":"2026-01-15T22:20:26","guid":{"rendered":"https:\/\/maritimehub.co.uk\/?p=47900"},"modified":"2026-01-15T22:20:48","modified_gmt":"2026-01-15T22:20:48","slug":"colregs-principles-conduct-of-vessels","status":"publish","type":"post","link":"https:\/\/maritimehub.co.uk\/colregs-principles-conduct-of-vessels\/","title":{"rendered":"COLREGs \u2013 Principles &amp; Conduct of Vessels"},"content":{"rendered":"\n<p><br><em>How collision avoidance actually works on a real bridge<\/em><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Contents<\/h2>\n\n\n\n<p>Use the links below to jump to any section:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>What COLREGs Really Is (and What It Is Not)<\/li>\n\n\n\n<li>Rule 2 \u2013 Responsibility: The Rule That Overrides All Others<\/li>\n\n\n\n<li>Rule 5 \u2013 Lookout: Human, Electronic, and Organisational<\/li>\n\n\n\n<li>Rule 6 \u2013 Safe Speed: Why \u201cWithin Limits\u201d Is Not Enough<\/li>\n\n\n\n<li>Rule 7 \u2013 Risk of Collision: CPA Lies and Mental Traps<\/li>\n\n\n\n<li>Rule 8 \u2013 Action to Avoid Collision: Early, Substantial, and Obvious<\/li>\n\n\n\n<li>Rule 9 \u2013 Narrow Channels: Where Theory Breaks Down<\/li>\n\n\n\n<li>Rule 10 \u2013 Traffic Separation Schemes: Compliance vs Safety<\/li>\n\n\n\n<li>Stand-On and Give-Way: Why the Names Mislead<\/li>\n\n\n\n<li>When the Other Vessel Is Wrong<\/li>\n\n\n\n<li>COLREGs in Restricted Visibility<\/li>\n\n\n\n<li>The Master, the OOW, and COLREGs Authority<\/li>\n\n\n\n<li>Common COLREGs Failure Patterns<\/li>\n\n\n\n<li>The COLREGs Mindset for Professional Watchkeepers<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">1. What COLREGs Really Is (and What It Is Not)<\/h2>\n\n\n\n<p>COLREGs is <strong>not<\/strong> a checklist.<br>It is <strong>not<\/strong> a decision tree.<br>It is <strong>not<\/strong> something you \u201capply after identifying lights.\u201d<\/p>\n\n\n\n<p>COLREGs is a <strong>behavioural framework<\/strong> governing how vessels avoid each other <strong>before<\/strong> danger becomes unavoidable.<\/p>\n\n\n\n<p>At sea, compliance with COLREGs is judged <strong>after the accident<\/strong>, not during the manoeuvre.<\/p>\n\n\n\n<p>Investigators do not ask:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u201cDid you know the rule?\u201d<\/p>\n<\/blockquote>\n\n\n\n<p>They ask:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u201cDid your actions reflect good seamanship and early collision avoidance?\u201d<\/p>\n<\/blockquote>\n\n\n\n<p>That difference matters.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">2. Rule 2 \u2013 Responsibility: The Rule That Overrides All Others<\/h2>\n\n\n\n<p>Rule 2 is the most powerful and most misunderstood rule in COLREGs.<\/p>\n\n\n\n<p>It states, in effect:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>You are responsible for avoiding collision<\/li>\n\n\n\n<li>Even if the other vessel is wrong<\/li>\n\n\n\n<li>Even if the rules appear to give you priority<\/li>\n<\/ul>\n\n\n\n<p>Rule 2 removes the idea of \u201chaving right of way.\u201d<\/p>\n\n\n\n<p>There is <strong>no such thing<\/strong> as an absolute right of way at sea.<\/p>\n\n\n\n<p>If you stand on proudly into a collision because \u201cthe rules said so,\u201d you have failed Rule 2.<\/p>\n\n\n\n<p>Professional watchkeepers treat Rule 2 as <strong>always active<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">3. Rule 5 \u2013 Lookout: Human, Electronic, and Organisational<\/h2>\n\n\n\n<p>A proper lookout is not a person standing near the window.<\/p>\n\n\n\n<p>It is a <strong>system<\/strong>.<\/p>\n\n\n\n<p>Rule 5 requires lookout by:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>sight<\/li>\n\n\n\n<li>hearing<\/li>\n\n\n\n<li>all available means<\/li>\n<\/ul>\n\n\n\n<p>\u201cAll available means\u201d includes:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>radar (properly set and interpreted)<\/li>\n\n\n\n<li>ECDIS awareness<\/li>\n\n\n\n<li>AIS understanding (with its limitations)<\/li>\n\n\n\n<li>bridge team communication<\/li>\n<\/ul>\n\n\n\n<p>A bridge with excellent equipment and poor teamwork <strong>does not have a proper lookout<\/strong>.<\/p>\n\n\n\n<p>A bridge with one overloaded OOW does not have a proper lookout.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">4. Rule 6 \u2013 Safe Speed: Why \u201cWithin Limits\u201d Is Not Enough<\/h2>\n\n\n\n<p>Safe speed is <strong>situational<\/strong>, not numerical.<\/p>\n\n\n\n<p>It depends on:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>visibility<\/li>\n\n\n\n<li>traffic density<\/li>\n\n\n\n<li>manoeuvrability<\/li>\n\n\n\n<li>background lights<\/li>\n\n\n\n<li>weather and sea state<\/li>\n\n\n\n<li>draft and UKC<\/li>\n\n\n\n<li>reliability of sensors<\/li>\n<\/ul>\n\n\n\n<p>If your speed does not allow you to:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>detect a risk<\/li>\n\n\n\n<li>assess it<\/li>\n\n\n\n<li>decide<\/li>\n\n\n\n<li>act<\/li>\n\n\n\n<li>and see the result<\/li>\n<\/ul>\n\n\n\n<p>then your speed is unsafe \u2014 regardless of engine capability or schedule pressure.<\/p>\n\n\n\n<p>Safe speed is about <strong>time margin<\/strong>, not knots.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">5. Rule 7 \u2013 Risk of Collision: CPA Lies and Mental Traps<\/h2>\n\n\n\n<p>Risk of collision exists when:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>bearing does not appreciably change<\/li>\n\n\n\n<li>CPA is reducing or small<\/li>\n\n\n\n<li>or when doubt exists<\/li>\n<\/ul>\n\n\n\n<p>Radar CPA is a <strong>tool<\/strong>, not truth.<\/p>\n\n\n\n<p>Common failures include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>trusting AIS CPA blindly<\/li>\n\n\n\n<li>misinterpreting ARPA vectors<\/li>\n\n\n\n<li>ignoring visual bearing stability<\/li>\n\n\n\n<li>assuming small CPA is acceptable \u201cbecause it will pass\u201d<\/li>\n<\/ul>\n\n\n\n<p>Rule 7 explicitly states:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>Assumptions must not be made on the basis of scanty information.<\/p>\n<\/blockquote>\n\n\n\n<p>If you are unsure \u2014 there <em>is<\/em> risk.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">6. Rule 8 \u2013 Action to Avoid Collision: Early, Substantial, and Obvious<\/h2>\n\n\n\n<p>This rule defines <strong>how<\/strong> to act.<\/p>\n\n\n\n<p>Actions must be:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>taken in ample time<\/li>\n\n\n\n<li>be large enough to be obvious<\/li>\n\n\n\n<li>avoid a succession of small changes<\/li>\n\n\n\n<li>result in passing at a safe distance<\/li>\n<\/ul>\n\n\n\n<p>Tiny course changes to \u201ctest the other vessel\u201d are a classic error.<\/p>\n\n\n\n<p>Late manoeuvres force extreme actions.<\/p>\n\n\n\n<p>Professional collision avoidance looks <strong>boring<\/strong> on radar \u2014 because it happens early.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">7. Rule 9 \u2013 Narrow Channels: Where Theory Breaks Down<\/h2>\n\n\n\n<p>Narrow channels expose the limits of rigid rule-following.<\/p>\n\n\n\n<p>Key realities:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>deep-draft vessels have constrained options<\/li>\n\n\n\n<li>bank suction and squat matter<\/li>\n\n\n\n<li>traffic density compresses reaction time<\/li>\n\n\n\n<li>small craft often misunderstand obligations<\/li>\n<\/ul>\n\n\n\n<p>Rule 9 does not grant dominance \u2014 it recognises <strong>constraints<\/strong>.<\/p>\n\n\n\n<p>A bridge team must think in terms of <strong>who can actually manoeuvre<\/strong>, not who \u201cshould.\u201d<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">8. Rule 10 \u2013 Traffic Separation Schemes: Compliance vs Safety<\/h2>\n\n\n\n<p>TSS compliance is mandatory \u2014 but not absolute.<\/p>\n\n\n\n<p>You must:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>proceed in the correct lane<\/li>\n\n\n\n<li>cross at right angles<\/li>\n\n\n\n<li>avoid unnecessary lane changes<\/li>\n<\/ul>\n\n\n\n<p>But Rule 10 does <strong>not<\/strong> excuse collision.<\/p>\n\n\n\n<p>Blindly following a lane while ignoring developing traffic risk violates Rule 2.<\/p>\n\n\n\n<p>TSSs reduce chaos \u2014 they do not remove responsibility.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">9. Stand-On and Give-Way: Why the Names Mislead<\/h2>\n\n\n\n<p>\u201cStand-on\u201d does not mean \u201cdo nothing.\u201d<\/p>\n\n\n\n<p>\u201cGive-way\u201d does not mean \u201cpanic manoeuvre.\u201d<\/p>\n\n\n\n<p>Stand-on vessels must:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>maintain course and speed initially<\/li>\n\n\n\n<li>monitor the situation<\/li>\n\n\n\n<li>act when collision risk develops<\/li>\n<\/ul>\n\n\n\n<p>Many collisions happen because the stand-on vessel waited too long, hoping the give-way vessel would comply.<\/p>\n\n\n\n<p>Hope is not a control measure.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">10. When the Other Vessel Is Wrong<\/h2>\n\n\n\n<p>This is where professionals separate themselves.<\/p>\n\n\n\n<p>If the other vessel:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>is not complying<\/li>\n\n\n\n<li>is manoeuvring unpredictably<\/li>\n\n\n\n<li>appears unaware<\/li>\n\n\n\n<li>or is constrained<\/li>\n<\/ul>\n\n\n\n<p>you must act <strong>before<\/strong> the situation becomes critical.<\/p>\n\n\n\n<p>COLREGs does not protect stubbornness.<\/p>\n\n\n\n<p>The goal is <strong>no collision<\/strong>, not proving correctness.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">11. COLREGs in Restricted Visibility<\/h2>\n\n\n\n<p>Restricted visibility changes everything.<\/p>\n\n\n\n<p>Key shifts:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>sound signals matter<\/li>\n\n\n\n<li>radar interpretation dominates<\/li>\n\n\n\n<li>visual confirmation may be impossible<\/li>\n\n\n\n<li>assumptions are dangerous<\/li>\n<\/ul>\n\n\n\n<p>In restricted visibility:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>you do not wait for certainty<\/li>\n\n\n\n<li>you reduce speed early<\/li>\n\n\n\n<li>you avoid close-quarters situations entirely<\/li>\n<\/ul>\n\n\n\n<p>Restricted visibility collisions are almost always <strong>speed and delay failures<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">12. The Master, the OOW, and COLREGs Authority<\/h2>\n\n\n\n<p>COLREGs authority flows like this:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The OOW applies COLREGs continuously<\/li>\n\n\n\n<li>The Master supports and intervenes as required<\/li>\n\n\n\n<li>Responsibility is never delegated away<\/li>\n<\/ul>\n\n\n\n<p>Calling the Master early is <strong>good seamanship<\/strong>, not weakness.<\/p>\n\n\n\n<p>Failure to call is frequently cited in collision reports.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">13. Common COLREGs Failure Patterns<\/h2>\n\n\n\n<p>Accident investigations repeatedly show:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>fixation on one sensor<\/li>\n\n\n\n<li>late decision-making<\/li>\n\n\n\n<li>small ineffective alterations<\/li>\n\n\n\n<li>overconfidence in \u201cstand-on\u201d status<\/li>\n\n\n\n<li>reluctance to challenge<\/li>\n\n\n\n<li>schedule pressure overriding judgement<\/li>\n<\/ul>\n\n\n\n<p>COLREGs failures are rarely ignorance \u2014 they are <strong>human factors failures<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">14. The COLREGs Mindset for Professional Watchkeepers<\/h2>\n\n\n\n<p>Professional application of COLREGs means:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>thinking in time margins, not rights<\/li>\n\n\n\n<li>acting early to create space<\/li>\n\n\n\n<li>assuming others may be wrong<\/li>\n\n\n\n<li>prioritising safety over correctness<\/li>\n\n\n\n<li>using the rules to <strong>support decisions<\/strong>, not replace them<\/li>\n<\/ul>\n\n\n\n<p>COLREGs is not about winning an argument at sea.<\/p>\n\n\n\n<p>It is about ensuring <strong>everyone goes home<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Tags<\/h2>\n\n\n\n<p>COLREGs principles \u00b7 conduct of vessels \u00b7 collision avoidance \u00b7 bridge watchkeeping \u00b7 OOW judgement \u00b7 maritime safety \u00b7 navigation rules<\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>How collision avoidance actually works on a real bridge Contents Use the links below to jump to any section: 1. What COLREGs Really Is (and What It Is Not) COLREGs is not a checklist.It is not a decision tree.It is not something you \u201capply after identifying lights.\u201d COLREGs is a behavioural framework governing how vessels [&hellip;]<\/p>\n","protected":false},"author":199,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"fifu_image_url":"","fifu_image_alt":"","c2c-post-author-ip":"","footnotes":""},"categories":[10,1,14],"tags":[8859],"class_list":["post-47900","post","type-post","status-publish","format-standard","hentry","category-bridge","category-latest","category-on-deck","tag-8859"],"acf":[],"_links":{"self":[{"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/posts\/47900","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/users\/199"}],"replies":[{"embeddable":true,"href":"https:\/\/maritimehub.co.uk\/?rest_route=%2Fwp%2Fv2%2Fcomments&post=47900"}],"version-history":[{"count":1,"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/posts\/47900\/revisions"}],"predecessor-version":[{"id":47901,"href":"https:\/\/maritimehub.co.uk\/?rest_route=\/wp\/v2\/posts\/47900\/revisions\/47901"}],"wp:attachment":[{"href":"https:\/\/maritimehub.co.uk\/?rest_route=%2Fwp%2Fv2%2Fmedia&parent=47900"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/maritimehub.co.uk\/?rest_route=%2Fwp%2Fv2%2Fcategories&post=47900"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/maritimehub.co.uk\/?rest_route=%2Fwp%2Fv2%2Ftags&post=47900"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}