https://wiki.alsresume.com/index.php?action=history&feed=atom&title=Under_keel_clearanceUnder keel clearance - Revision history2026-04-07T16:45:33ZRevision history for this page on the wikiMediaWiki 1.42.0https://wiki.alsresume.com/index.php?title=Under_keel_clearance&diff=6727&oldid=prevAdmin: 1 revision imported2025-03-23T11:27:36Z<p>1 revision imported</p>
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</td></tr></table>Adminhttps://wiki.alsresume.com/index.php?title=Under_keel_clearance&diff=6726&oldid=prevwikipedia>Fgnievinski at 01:43, 21 January 20252025-01-21T01:43:43Z<p></p>
<p><b>New page</b></p><div>{{Short description|Height of water under a keel}}<br />
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In [[Seamanship|seafaring]], '''under keel clearance''' ('''UKC''') is the vertical distance between [[seabed]] and the [[keel]] or [[Draft (hull)|hull]] of a [[ship]].<ref name="Weintrit 2009"/><ref name="RG">{{Cite web |url=https://www.researchgate.net/publication/328575846_Simplified_approach_to_operationalise_UKC_calculations |title=Simplified approach to operationalise UKC calculations Conference Paper |access-date=4 April 2024 |publisher=PIANC}}</ref><ref name="NI">{{Cite web |url=https://www.nautinst.org/resources-page/all-you-ever-wanted-to-know-about-under-keel-clearance-but-were-afraid-to-ask.html |title=All you ever wanted to know about Under Keel Clearance but were afraid to ask |access-date=4 April 2024 |publisher=Nautical Institute}}</ref><br />
It is used to ensure sufficient [[navigable]] water is available for ships at sea.<ref name="Gilardoni Presedo 2017">{{cite book | last=Gilardoni | first=Eduardo O. | last2=Presedo | first2=Juan P. | title=Navigation in Shallow Waters | publisher=[[Witherby Publishing Group]] | publication-place=Livingston, Scotland | date=2017 | isbn=978-1-85609-667-6|page=67}}</ref><ref name="ECDISandUKC">{{cite book | title=ECDIS Safety Settings and UKC Management | publisher=[[Witherby Publishing Group]] | publication-place=Livingston, Scotland | date=2017 | isbn=9781914993695}}</ref><ref name="Weintrit 2009">{{cite book | last=Weintrit | first=Adam | title=Marine Navigation and Safety of Sea Transportation | publisher=CRC Press | publication-place=Boca Raton : London | date=2009-06-02 | isbn=978-0-203-86934-5 | oclc=435419166 | page=484}}</ref><ref name="MarineInsight">{{Cite web |url=https://www.marineinsight.com/naval-architecture/what-is-underwater-keel-clearance/|title=What Is Underwater Keel Clearance? |access-date=4 April 2024 |publisher=Marine Insight}}</ref> <br />
[[Master mariner]]s should ensure there is sufficient minimum UKC for their [[ships]]; [[ports]] should ensure sufficient minimum UKC for the type and [[draft (hull)|draft]] of ships due to arrive in the port.<ref name="ECDIS2023">{{cite book | title=ECDIS Passage Planning and Watchkeeping | publisher=[[Witherby Publishing Group]] | publication-place=Livingston, Scotland | date=2023 | isbn=9781856098168|page=25}}</ref><ref name="NI"/> Ships typically calculate their UKC to meet criteria for ports to minimise the risk of maritime incidents.<ref name="NI"/> The minimum UKC determined includes a safety margin.<ref name="ECDIS2023"/><br />
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==Methods of calculation==<br />
At a basic level, it is typically calculated in metres using the formula:<ref name="Weintrit 2009"/> <br />
:UKC = [[Chart datum|Charted Depth]] − [[Draft (hull)|Draft]] -/+ Height of [[Tide]]<br />
Ship masters and deck officers can obtain the depth of water from [[Electronic navigational chart]]s.<ref name="ECDISandUKC"/> More dynamic or advanced calculations include safety margins for manoeuvring effects and [[Squat effect|squat]].<ref name="ECDIS2023"/><br />
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Computer systems and software can be used to manage and calculate UKC for ships and ports.<ref name="MarExec">{{Cite web|url=https://maritime-executive.com/corporate/under-keel-clearance-technology-wins-international-award |title=Under Keel Clearance Technology Wins International Award |access-date=4 April 2024 |publisher=Maritime Executive}}</ref><ref name="DCN">{{Cite web|url=https://www.thedcn.com.au/news/ports/under-keel-clearance-system-upgrade-for-bunbury/ |title=Under Keel Clearance System Upgrade for Bunbury |access-date=4 April 2024 |publisher=Daily Cargo News}}</ref> These include systems that dynamically manage UKC using models, forecasting and calculations.<ref name="HarbourMaster">{{Cite web|url=https://harbourmaster.org/sponsors/omc |title=OMC |access-date=4 April 2024 |publisher=International Harbour Masters Association}}</ref><br />
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The [[International Hydrographic Organization]] (IHO) sets a Standard for UKC Management for software and systems: S-129 Under Keel Clearance Management.<ref name="IHO">{{Cite web |url=https://ihr.iho.int/articles/dynamic-draft-and-under-keel-clearance-a-hydrographic-view/ |title=Dynamic Draft and Under Keel Clearance |access-date=4 April 2024 |publisher=International Hydrographic Organization (IHO)}}</ref><br />
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==Uses and requirements==<br />
For US waters, the US [[Code of Federal Regulations]] require ships and their masters to calculate UKC based on the ship's deepest navigational draft.{{CodeFedReg |33|157|450}} The regulations require the master to discuss the UKC calculation with the [[maritime pilot]] as the ship approaches US ports/waters.{{CodeFedReg |33|157|450}} <br />
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The [[Australian Maritime Safety Authority]] state that maintaining adequate UKC is important for safe navigation in the [[Torres Strait]].<ref name="AMSA">{{Cite web |url=https://www.amsa.gov.au/file/2927/download?token=uVFmyG_S#:~:text=What%20is%20Under%20Keel%20Clearance,ship's%20hull%20and%20the%20seabed. |title=Under Keel Clearance Management System Fact Sheet |access-date=4 April 2024 |publisher=Australian Maritime Safety Authority}}</ref><br />
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Inadequate UKC, caused by [[Waves and shallow water|shallow water]] and squat may lead to [[ship grounding]]s.<ref name="MAIB">{{Cite web|url=https://maritime-executive.com/article/maib-shallow-water-effects-contributed-to-ro-ro-s-grounding |title=MAIB: Shallow Water Effects Contributed to Ro/Ro's Grounding |access-date=4 April 2024 |publisher=Maritime Executive}}</ref> In 2019, the UK [[Marine Accident Investigation Branch]] found that indequate UKC contributed towards the grounding of the ro/ro freight ferry [[MS Stena Performer]].<ref name="MAIB"/><br />
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Changes in water level may cause issues with adequate UKC for ships. For example, recent water level reductions in the [[Panama Canal]] have reduced UKC for ships meaning some ships are not able to transit the canal.<ref name="Riviera">{{Cite web|url=https://www.rivieramm.com/news-content-hub/news-content-hub/panama-canal-water-levels-causing-long-term-concern-61025 |title=Panama Canal water levels cause long-term concern |access-date=4 April 2024 |publisher=Riviera}}</ref><ref name="NYT">{{Cite web|url=https://www.nytimes.com/interactive/2024/01/26/climate/panama-canal-drought-shipping.html |title=Panama Canal Drought Slows Cargo Traffic |access-date=4 April 2024 |publisher=The New York Times}}</ref><br />
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==References==<br />
{{Reflist}}<br />
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{{Ship measurements}}<br />
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[[Category:Nautical terminology]]<br />
[[Category:Navigation]]<br />
[[Category:Ship measurements]]<br />
[[Category:Vertical position]]</div>wikipedia>Fgnievinski