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The Significance of Ship Maneuvering The Significance of Ship Maneuvering

to Collision Avoidance Decisionsto Collision Avoidance Decisions

xuan xiao dongxuan xiao dong

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► First, the conduct and responsibility of collision First, the conduct and responsibility of collision avoidance in the Regulations are based on the avoidance in the Regulations are based on the relationship of relationship of two vesselstwo vessels. So it will be difficult to . So it will be difficult to provide clear and definite instructions to the duty provide clear and definite instructions to the duty officer and the pilot to make collision avoidance officer and the pilot to make collision avoidance decisions in decisions in multi-shipmulti-ship encounter situations. encounter situations.

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► Second, the conduct in the Regulations is mostly Second, the conduct in the Regulations is mostly based on the environment of based on the environment of broad watersbroad waters, hence , hence not suitable when the ship is going along the not suitable when the ship is going along the coastcoast, , narrow channelsnarrow channels or or reef island areasreef island areas, where the , where the behavior of collision avoidance is very limited.behavior of collision avoidance is very limited.

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► Third, an essential pre-condition for effective Third, an essential pre-condition for effective implementation of the Regulations is that the two implementation of the Regulations is that the two vessels involved should vessels involved should fully understand and strictly fully understand and strictly obey the Regulations.obey the Regulations. However, that is highly However, that is highly unlikely in real navigational situations. Worse still, unlikely in real navigational situations. Worse still, some officers of small vessels know nothing about some officers of small vessels know nothing about the Regulations.the Regulations.

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► Fourth, vessels are permitted to depart from the Fourth, vessels are permitted to depart from the rules when necessary to avoid immediate danger, rules when necessary to avoid immediate danger, but it remains a question how to make such a but it remains a question how to make such a departure and how to smooth out immediate departure and how to smooth out immediate danger. There is danger. There is no answerno answer in the Regulations. in the Regulations.

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► Fifth, the modification and perfection of the Fifth, the modification and perfection of the Regulations usually lag behind the development of Regulations usually lag behind the development of navigational technology, such as navigational technology, such as ARPAARPA, , AIS,AIS, and and VDRVDR, providing more accurate information for , providing more accurate information for making collision avoidance decisions and accident making collision avoidance decisions and accident handling at sea; moreover, it will have some impact handling at sea; moreover, it will have some impact on the duty officer and the pilot for their behavior on the duty officer and the pilot for their behavior and habit in collision preventing. However, all the and habit in collision preventing. However, all the abovementioned continually fails to be found in the abovementioned continually fails to be found in the Regulations.Regulations.

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► The conception of ship maneuveringThe conception of ship maneuvering is a set of thinki is a set of thinking patterns for making analysis, assessment, judgmeng patterns for making analysis, assessment, judgment formed by long-term practice and experiences sunt formed by long-term practice and experiences summarization. mmarization.

the sense ofthe sense of space space,,

the sense ofthe sense of time time, ,

thethe global global viewpointviewpoint ，， thethe empathy empathy viewpoint.viewpoint.

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The sense of The sense of spacespace aboveabove water water

► The sense of space The sense of space above water is the above water is the conception of conception of formform and and sizesize of one’s own vessel of one’s own vessel and the encounter and the encounter vessel above water for vessel above water for the officer and the pilot the officer and the pilot

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The sense of The sense of spacespace underunder water water

► The sense of space under water is related to ship’s The sense of space under water is related to ship’s draftdraft and and displacementdisplacement. .

► Many important factors can impact ship maneuvering such as Many important factors can impact ship maneuvering such as navigable water areanavigable water area, , current pressurecurrent pressure and and possible shallow possible shallow water effectwater effect are all determined by draft. The establishment of are all determined by draft. The establishment of such conception will remind us to consider the dangers undesuch conception will remind us to consider the dangers underwater all the time and balancing all kinds of risks overall. rwater all the time and balancing all kinds of risks overall.

► Ship’s Ship’s inertiainertia and and maneuverability maneuverability owes much to its displaceowes much to its displacement, so such conception will help us to determine the “safe sment, so such conception will help us to determine the “safe speed” and behaviors of collision avoidance by “reducing speepeed” and behaviors of collision avoidance by “reducing speed” or “altering the course”.d” or “altering the course”.

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the sense of the sense of timetime ► First, oftentimes, the sense of time has to do with the control First, oftentimes, the sense of time has to do with the control

of speed and correlates with the sense of space. When space of speed and correlates with the sense of space. When space remains constant, the faster the ship’s speed, the smaller a remains constant, the faster the ship’s speed, the smaller a ship’s handler feels about the space. For ships with slow ship’s handler feels about the space. For ships with slow speed, the opposite is true. When forward situation is not speed, the opposite is true. When forward situation is not clear, it is clear, it is a bright “conception of time”a bright “conception of time” to slow down for to slow down for saving more time to make a better decision to avoid collision.saving more time to make a better decision to avoid collision.

► Second, when the officer and the pilot encounter Second, when the officer and the pilot encounter multi-shipmulti-ship encounter situations, it is important to give all the collision encounter situations, it is important to give all the collision risks risks anan overall considerationoverall consideration in order of in order of prioritypriority according to according to the immediacy of each risk. the immediacy of each risk.

► Third, the factors which can impact ship maneuvering such Third, the factors which can impact ship maneuvering such as as current regularitycurrent regularity, , traffic flow peculiaritytraffic flow peculiarity and and meteorology meteorology change, e.g. twilight, sunrise change, e.g. twilight, sunrise andand sunset sunset are all are all interconnected with the conception of time. With it, the interconnected with the conception of time. With it, the officer and the pilot will be more confident and primed when officer and the pilot will be more confident and primed when making decisions to avoid collision.making decisions to avoid collision.

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The The global global viewpointviewpoint

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The The global global viewpointviewpoint

► In addition to collision, there are many In addition to collision, there are many other other maneuvering risksmaneuvering risks in navigational practices, such as in navigational practices, such as fairway depth, traffic flow, leeway, driftfairway depth, traffic flow, leeway, drift and and heavy heavy weather.weather.

► We should be aware that We should be aware that collision avoidance is not collision avoidance is not the whole of navigation; it is only one of many the whole of navigation; it is only one of many methods to ensure the safety of navigation.methods to ensure the safety of navigation. Making Making collision avoidance decisions is a part of navigation collision avoidance decisions is a part of navigation safety and should take the whole situation on board.safety and should take the whole situation on board.

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The The global global viewpointviewpoint

► When a vessel navigates in an area with big traffic When a vessel navigates in an area with big traffic flow, oftentimes the navigator will meet a lot of flow, oftentimes the navigator will meet a lot of complex situationscomplex situations such as multi-ship encounter such as multi-ship encounter situation or continuous collision risk.situation or continuous collision risk.

► Some collision avoidance behaviors are highly Some collision avoidance behaviors are highly efficient and in conformity with the Regulations efficient and in conformity with the Regulations in in the short-termthe short-term; however, it will put vessels into ; however, it will put vessels into another another close-quarters situation and even into close-quarters situation and even into immediate danger later. It is necessary for us to have immediate danger later. It is necessary for us to have a ‘global picture’a ‘global picture’ to handle such complex situations; to handle such complex situations; sometimes, a departure from the rules will be sometimes, a departure from the rules will be necessary for the whole situation. necessary for the whole situation.

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The The empathyempathy viewpoint viewpoint ► When two vessels encounter, the When two vessels encounter, the

final outcome is caused by the final outcome is caused by the behavior of behavior of both sidesboth sides..

► One sideOne side should not only consider should not only consider its own behavior whether to follow its own behavior whether to follow the Regulations or whether it is the Regulations or whether it is appropriate for the prevailing appropriate for the prevailing circumstances and conditions, but circumstances and conditions, but also understand also understand the other side’s the other side’s backgroundbackground, , thoughtsthoughts, , behaviors behaviors and and psychologypsychology..

► Collision avoidance is like playing Collision avoidance is like playing chess—the key to success is to chess—the key to success is to know about both yourselfknow about both yourself and and the the other side. other side.

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ConclusionConclusion

► One of the commonest misconceptions in the teaching One of the commonest misconceptions in the teaching and research of navigation is regarding and research of navigation is regarding the collision the collision regulationsregulations as as collision avoidance sciencecollision avoidance science. A lot of . A lot of limitations of collision regulations are largely limitations of collision regulations are largely highlighted by this improper cognition. As the collision highlighted by this improper cognition. As the collision regulations are only a legal norm after all instead of a regulations are only a legal norm after all instead of a perfect theoretical and technical system, it is difficult perfect theoretical and technical system, it is difficult for them to handle all the collision avoidance situations for them to handle all the collision avoidance situations in real navigational work. in real navigational work.

► Integrating ship’s maneuvering conceptions into Integrating ship’s maneuvering conceptions into collision avoidance decisioncollision avoidance decision can solve a lot of problems can solve a lot of problems caused by limitations of the Regulations properly. And caused by limitations of the Regulations properly. And that may be one of the tendencies for the development that may be one of the tendencies for the development of collision avoidance science in the future.of collision avoidance science in the future.

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Thank you very muchThank you very muchfor your attention!for your attention!

the end