首页 ＞ 商品介绍 > BRM for 21 century > Knowledge Base and Situation Awarenese for Master > Chapter 11 Dynamic Navigation for Master
Chapter 11 Dynamic Navigation for Master
以下是该段文字的繁体中文翻译：
第 11 章：船长的动态航行（Dynamic Navigation for Master）
图 11-01 新加坡港引水站的避碰模拟器场景
这些避碰演练场景设定於新加坡海峡、东部甲类引水登船区（Pilot Eastern Boarding Ground Alfa）外围，如图 11-01 所示。演练对象为来自知名航商的高级船长或初级值班船员（OOW）。在这些演练中，资历并不保证成功；事实上，初级 OOW 反而可能更快适应新观念。无论如何，这些演练为参演人员提供了一个宝贵的机会，可在不承担真实航行风险的情况下，审视并检讨其视觉与雷达了望技能。
在人为因素（Human Element）的研究中，真实的避碰场景常会产生过度的心理与生理压力，进而使我们的记忆结构过载。结果导致经验丰富的航海人员可能会遗漏重要资讯，而经验较浅者则可能难以吸收与吸收新资讯。
关於演练前指导员简报的部分，有些船长能很好地记住指示，有些则不然。演练期间，有些指导员偏好采取不干涉态度，有些则在出现错误迹象时便立即介入。就个人而言，我属於后者；我主张在必要时暂停演练，召集所有驾驶台人员讨论问题所在以及如何改善状况。我深知人类在面对作业程序时，其短期与长期记忆皆有所局限。这种局限性引发了一个疑问：部分人员究竟是如何晋升至船长职位的？若他们缺乏正确的长期程序记忆，从简报或讲座中所吸收的任何资讯都可能不可靠，因为这些资讯可能仅停留在他们的短期记忆中。
「操舵系统从未在物理层面上失灵，而是被切换到了不同的控制站，但值班人员并未察觉此一配置。更严重的是，将操舵控制转移至副操舵手（Lee Helm）时，导致舵角回中（位於中线）。由於在切换前，操舵手一直保持右舵 1 至 4 度以维持航向，因此舵角回中导致船只航向向左偏离。此外，当操舵手回报失去操舵能力时，舰长将船速减至 10 节，随后进一步减至 5 节。然而，副操舵手仅降低了左轴的转速，因为双轴节流阀并未并联（Ganged）。右轴在接下来的 68 秒内仍以 20 节的速度运转，之后转速才被降低。这种错误的舵向与双轴独立运转的组合，导致船只在接近包含 ALNIC 号在内的三艘船只的拥挤航道中，非指令性地向左（左舷）急转。
尽管 USS JOHN S. MCCAIN 号当时已与 ALNIC 号处於碰撞航向上，舰长与驾驶台上的其他人员却失去了情境意识（Situational Awareness）。在混乱中，驾驶台上没有人清楚了解作用於船只上的外力，亦未能掌握 ALNIC 号相对於 JOHN S. MCCAIN 号的航向与航速。」
—— 《USS JOHN S. MCCAIN 号与机动船 ALNIC MC 号碰撞事件报告》（未定密）
此事件严正提醒了我们，情境意识与有效沟通在海上作业中具有至关重要的权重。
在 HELM（驾驶台资源管理与人为因素）课程中，我强调舰长/船长只有一分钟的时间来纠正错误。在真实场景中，值班船员（OOW）依赖短期记忆，持续处理关於航向、舵角、船速、位置及周围船只等瞬息万变的资讯，同时须依赖长期记忆来排定资料的优先顺序，以确保船舶在当前状况下的安全。这个过程感觉就像走路或进食一样自动化；它常作为我们的习惯而潜意识地发生。然而，若潜意识未能正确浮现，不确定性便可能引发恐慌、恐惧或困惑。这也是本书各章节以悬疑方式编排的原因。我不相信有人只需阅读一次，就能完全掌握在驾驶台值班时应采取的所有行动。
根据美国海军的定义，情境意识（Situational Awareness）分为三个层次：
认知（Knowledge）： 我们的感官察觉到状况，并集中我们的注意力。
理解（Understanding）： 我们的潜意识处理关键要素，并在出现异常时即时识别。
精通（Proficiency）： 我们的身体根据既定程序做出反应，将无意识错误的风险降至最低，符合 STCW 标准。
通常，我们的眼睛可能看到了某个现象，却无法理解其重要性——图 3-1 所示的桑吉号（SANCHI）案例即是一例，该图描绘了桑吉号与长峰水晶号（CF CRYSTAL）的航迹。相反地，我们也可能忽视即将到来的危险，如图 7-09 所示的 Ever Smart 号案例，该图描绘了碰撞前两分钟的情况。
要获得正确的情境意识，我们需要进行针对以下重点的适当训练：
验证陈述，以增强短期记忆中的注意力。
练习技能，以发展长期情境记忆（Long-term contextual memory）。
遵循正确顺序，以养成长期程序记忆（Long-term procedural memory）。
图 11-02 点与线的碰撞风险
碰撞定义： 当两个目标在同一时间到达同一地点时，即发生碰撞，如图 11-02 所示。我们可以定义：
碰撞点风险（Collision Point Risk）： 这是两艘船只航向线相交的点，在图中以黄色圆圈表示。碰撞点风险并不意味著已经发生碰撞；我们必须在其碰撞线上验证其位置。
碰撞线风险（Collision Line Risk）： 两船 3 分钟速度向量相交的线，类似图 2-15 中的船只。3 分钟是转向所需的时间。在此时间范围内速度向量相交，意味著由於操舵困难，极易发生碰撞。换句话说，两艘船只在 3 分钟的时间差内到达同一个碰撞点，即视为存在碰撞风险。
碰撞区风险（Collision Area Risk）： 这涵盖了多艘船只的速度向量在最后 3 分钟内重叠的区域，如以下所示：
图 11-03：港外近距离交叉船只矩阵
图 7-01：远距离交叉船只的旋转木马效应
图 6-06：出港船只长纵队
图 5-18：共产党口袋战术中的摇晃船舶
图 3-04：双目标交叉案例
图 2-19：雷达回波中合并的碰撞目标（这些图号需要重新审视）
这些多重碰撞风险区域应由 OOW 予以避开（例如：绕道而行；若无法避开，则呼叫船长）。相反地，这些区域应由船长凭藉专业技能进行航行，船长必须找到合适的海域空间或时机通过。船舶聚集通常是暂时的；因此，在没有足够海域空间时，减速永远是最好的补救措施。
图 11-03 方格中的碰撞区风险
碰撞点风险的概念： 这能提高对潜在交叉状况的警觉。
港口附近存在许多碰撞点（此陈述属於常识）。
并非所有碰撞点都带有碰撞风险（另一个陈述）。
只有当本船与另一艘船只同时到达该点时，才会产生碰撞风险（进一步的陈述）。
碰撞点可在航程计画期间提高对潜在交叉状况的警觉（这项技能需要利用我们的感官检查至少一项安全关切基准）。
要确定碰撞风险，应专注於我们速度向量的末端（技能）。
另一艘船只速度向量的末端，代表其在我们 ARPA 设定时间后的预测位置（技能）。
图 11-04 如何从船只 6 分钟速度向量判读碰撞点风险
在图 11-04 中，速度向量设定为 6 分钟。必要时，我们会使用较长的速度向量时间设定来增强碰撞警觉。
1号碰撞点： 与本船（红线）无碰撞风险。
本船将在 6 分钟的一半时间（即 3 分钟）内到达碰撞点。
目标船只将在距今 5 分钟以上才到达碰撞点（根据其速度向量上的碰撞点位置估算）。
本船将在 3 分钟后驶过目标船只的船首（这是根据 6 分钟速度向量判断碰撞点的技能）。
2号碰撞点： 包含不确定的碰撞风险（直觉是我们必须练习的技能）。
本船将在 3.5 分钟内到达碰撞点（技能：利用本船速度向量测量碰撞点距离）。
目标船只也将在大致相同的时间到达碰撞点（技能：利用目标船只速度向量测量碰撞点距离）。
本船与该船存在碰撞风险（根据 6 分钟速度向量判断碰撞点的技能）。
3号碰撞点： 同样包含不确定的碰撞风险（直觉）。
本船将在 5 分钟内到达碰撞点（利用本船速度向量测量碰撞点距离）。
碰撞点位於目标船只速度向量的末端（利用目标船只速度向量测量碰撞点距离）。
本船与该船存在碰撞风险（如图 2-15 关於太空船状态的知识）。
针对 2 号和 3 号碰撞点的风险，潜在的避让方式为降低本船航速。
第 11 章：船长的动态航行（Dynamic Navigation for Master）
图 11-01 新加坡港引水站的避碰模拟器场景
这些避碰演练场景设定於新加坡海峡、东部甲类引水登船区（Pilot Eastern Boarding Ground Alfa）外围，如图 11-01 所示。演练对象为来自知名航商的高级船长或初级值班船员（OOW）。在这些演练中，资历并不保证成功；事实上，初级 OOW 反而可能更快适应新观念。无论如何，这些演练为参演人员提供了一个宝贵的机会，可在不承担真实航行风险的情况下，审视并检讨其视觉与雷达了望技能。
在人为因素（Human Element）的研究中，真实的避碰场景常会产生过度的心理与生理压力，进而使我们的记忆结构过载。结果导致经验丰富的航海人员可能会遗漏重要资讯，而经验较浅者则可能难以吸收与吸收新资讯。
关於演练前指导员简报的部分，有些船长能很好地记住指示，有些则不然。演练期间，有些指导员偏好采取不干涉态度，有些则在出现错误迹象时便立即介入。就个人而言，我属於后者；我主张在必要时暂停演练，召集所有驾驶台人员讨论问题所在以及如何改善状况。我深知人类在面对作业程序时，其短期与长期记忆皆有所局限。这种局限性引发了一个疑问：部分人员究竟是如何晋升至船长职位的？若他们缺乏正确的长期程序记忆，从简报或讲座中所吸收的任何资讯都可能不可靠，因为这些资讯可能仅停留在他们的短期记忆中。
「操舵系统从未在物理层面上失灵，而是被切换到了不同的控制站，但值班人员并未察觉此一配置。更严重的是，将操舵控制转移至副操舵手（Lee Helm）时，导致舵角回中（位於中线）。由於在切换前，操舵手一直保持右舵 1 至 4 度以维持航向，因此舵角回中导致船只航向向左偏离。此外，当操舵手回报失去操舵能力时，舰长将船速减至 10 节，随后进一步减至 5 节。然而，副操舵手仅降低了左轴的转速，因为双轴节流阀并未并联（Ganged）。右轴在接下来的 68 秒内仍以 20 节的速度运转，之后转速才被降低。这种错误的舵向与双轴独立运转的组合，导致船只在接近包含 ALNIC 号在内的三艘船只的拥挤航道中，非指令性地向左（左舷）急转。
尽管 USS JOHN S. MCCAIN 号当时已与 ALNIC 号处於碰撞航向上，舰长与驾驶台上的其他人员却失去了情境意识（Situational Awareness）。在混乱中，驾驶台上没有人清楚了解作用於船只上的外力，亦未能掌握 ALNIC 号相对於 JOHN S. MCCAIN 号的航向与航速。」
—— 《USS JOHN S. MCCAIN 号与机动船 ALNIC MC 号碰撞事件报告》（未定密）
此事件严正提醒了我们，情境意识与有效沟通在海上作业中具有至关重要的权重。
在 HELM（驾驶台资源管理与人为因素）课程中，我强调舰长/船长只有一分钟的时间来纠正错误。在真实场景中，值班船员（OOW）依赖短期记忆，持续处理关於航向、舵角、船速、位置及周围船只等瞬息万变的资讯，同时须依赖长期记忆来排定资料的优先顺序，以确保船舶在当前状况下的安全。这个过程感觉就像走路或进食一样自动化；它常作为我们的习惯而潜意识地发生。然而，若潜意识未能正确浮现，不确定性便可能引发恐慌、恐惧或困惑。这也是本书各章节以悬疑方式编排的原因。我不相信有人只需阅读一次，就能完全掌握在驾驶台值班时应采取的所有行动。
根据美国海军的定义，情境意识（Situational Awareness）分为三个层次：
认知（Knowledge）： 我们的感官察觉到状况，并集中我们的注意力。
理解（Understanding）： 我们的潜意识处理关键要素，并在出现异常时即时识别。
精通（Proficiency）： 我们的身体根据既定程序做出反应，将无意识错误的风险降至最低，符合 STCW 标准。
通常，我们的眼睛可能看到了某个现象，却无法理解其重要性——图 3-1 所示的桑吉号（SANCHI）案例即是一例，该图描绘了桑吉号与长峰水晶号（CF CRYSTAL）的航迹。相反地，我们也可能忽视即将到来的危险，如图 7-09 所示的 Ever Smart 号案例，该图描绘了碰撞前两分钟的情况。
要获得正确的情境意识，我们需要进行针对以下重点的适当训练：
验证陈述，以增强短期记忆中的注意力。
练习技能，以发展长期情境记忆（Long-term contextual memory）。
遵循正确顺序，以养成长期程序记忆（Long-term procedural memory）。
图 11-02 点与线的碰撞风险
碰撞定义： 当两个目标在同一时间到达同一地点时，即发生碰撞，如图 11-02 所示。我们可以定义：
碰撞点风险（Collision Point Risk）： 这是两艘船只航向线相交的点，在图中以黄色圆圈表示。碰撞点风险并不意味著已经发生碰撞；我们必须在其碰撞线上验证其位置。
碰撞线风险（Collision Line Risk）： 两船 3 分钟速度向量相交的线，类似图 2-15 中的船只。3 分钟是转向所需的时间。在此时间范围内速度向量相交，意味著由於操舵困难，极易发生碰撞。换句话说，两艘船只在 3 分钟的时间差内到达同一个碰撞点，即视为存在碰撞风险。
碰撞区风险（Collision Area Risk）： 这涵盖了多艘船只的速度向量在最后 3 分钟内重叠的区域，如以下所示：
图 11-03：港外近距离交叉船只矩阵
图 7-01：远距离交叉船只的旋转木马效应
图 6-06：出港船只长纵队
图 5-18：共产党口袋战术中的摇晃船舶
图 3-04：双目标交叉案例
图 2-19：雷达回波中合并的碰撞目标（这些图号需要重新审视）
这些多重碰撞风险区域应由 OOW 予以避开（例如：绕道而行；若无法避开，则呼叫船长）。相反地，这些区域应由船长凭藉专业技能进行航行，船长必须找到合适的海域空间或时机通过。船舶聚集通常是暂时的；因此，在没有足够海域空间时，减速永远是最好的补救措施。
图 11-03 方格中的碰撞区风险
碰撞点风险的概念： 这能提高对潜在交叉状况的警觉。
港口附近存在许多碰撞点（此陈述属於常识）。
并非所有碰撞点都带有碰撞风险（另一个陈述）。
只有当本船与另一艘船只同时到达该点时，才会产生碰撞风险（进一步的陈述）。
碰撞点可在航程计画期间提高对潜在交叉状况的警觉（这项技能需要利用我们的感官检查至少一项安全关切基准）。
要确定碰撞风险，应专注於我们速度向量的末端（技能）。
另一艘船只速度向量的末端，代表其在我们 ARPA 设定时间后的预测位置（技能）。
图 11-04 如何从船只 6 分钟速度向量判读碰撞点风险
在图 11-04 中，速度向量设定为 6 分钟。必要时，我们会使用较长的速度向量时间设定来增强碰撞警觉。
1号碰撞点： 与本船（红线）无碰撞风险。
本船将在 6 分钟的一半时间（即 3 分钟）内到达碰撞点。
目标船只将在距今 5 分钟以上才到达碰撞点（根据其速度向量上的碰撞点位置估算）。
本船将在 3 分钟后驶过目标船只的船首（这是根据 6 分钟速度向量判断碰撞点的技能）。
2号碰撞点： 包含不确定的碰撞风险（直觉是我们必须练习的技能）。
本船将在 3.5 分钟内到达碰撞点（技能：利用本船速度向量测量碰撞点距离）。
目标船只也将在大致相同的时间到达碰撞点（技能：利用目标船只速度向量测量碰撞点距离）。
本船与该船存在碰撞风险（根据 6 分钟速度向量判断碰撞点的技能）。
3号碰撞点： 同样包含不确定的碰撞风险（直觉）。
本船将在 5 分钟内到达碰撞点（利用本船速度向量测量碰撞点距离）。
碰撞点位於目标船只速度向量的末端（利用目标船只速度向量测量碰撞点距离）。
本船与该船存在碰撞风险（如图 2-15 关於太空船状态的知识）。
针对 2 号和 3 号碰撞点的风险，潜在的避让方式为降低本船航速。
售价 NT$ 300
Chapter 11: Dynamic Navigation for Master
Figure 11-01 Collision Avoidance simulator scene at SGP harbor pilot station
These collision avoidance scenarios are set in the Singapore Strait, just outside the Pilot Eastern
Boarding Ground Alfa, as depicted in Figure 11-01. These exercises are conducted by senior masters
or junior officers of the watch (OOW) from well-known shipping companies. In these exercises,
seniority does not guarantee success; indeed, junior OOWs may adapt to new concepts more rapidly.
Regardless, these exercises provide a valuable opportunity for participants to review their visual and
radar lookout skills without the risks associated with real navigation.
In studies of the human element, real collision avoidance scenarios often generate excessive
mental and physical pressure, which can overload our memory structure. As a result, important
information may be lost for experienced mariners, while those with less experience may struggle to
retain new information.
Regarding instructor briefings before the exercises, some captains can recall the instructions well,
while others cannot. During the exercises, some instructors prefer a hands-off approach, while others
intervene at the first sign of error. Personally, I fall into the latter category; I believe in stopping the
exercise when necessary to gather all bridge personnel and discuss what went wrong and how we can
improve the situation. I recognize that humans operate with limited short-term and long-term memory
regarding procedures. This limitation raises questions about how some individuals ascend to the rank
of Captain. If they lack the correct long-term procedures, any information they absorb from briefings or
lectures will likely remain unreliable, as it may only reside in their short-term memory.
“Steering was never physically lost. Rather, it had been shifted to a different control station, and
the watchstanders failed to recognize this configuration. Compounding the issue, the steering control
transfer to the Lee Helmcaused the rudder to go amidships (centerline). Since the Helmsman had been
steering with 1-4 degrees of right rudder to maintain course before the transfer, the amidships rudder
caused the ship’s course to deviate to the left. Additionally, when the Helmsman reported the loss of
steering, the Commanding Officer slowed the ship to 10 knots and eventually to 5 knots. However, the
Lee Helmsman reduced the speed of only the port shaft, as the throttles were not coupled together
(ganged). The starboard shaft continued at 20 knots for another 68 seconds before its speed was also
reduced. This combination of incorrect rudder direction and the two shafts operating independently led
to an uncommanded turn to the left (port) into a heavily congested traffic area, in close proximity to
three ships, including the ALNIC.
Although the USS JOHN S. MCCAIN was now on a collision course with the ALNIC, the
Commanding Officer and others on the ship’s bridge lost situational awareness. No one on the bridge
clearly understood the forces acting on the ship, nor did they grasp the ALNIC's course and speed
relative to the JOHN S. MCCAIN during the confusion.”
— Report on the Collision between USS JOHN S. MCCAIN and Motor Vessel ALNIC MC,
UNCLASSIFIED.
This incident serves as a poignant reminder of the critical importance of situational awareness and
effective communication in maritime operations.
In the HELM class, I emphasize that the Commanding Officer has only one minute to correct
mistakes. In real scenarios, the Officer of the Watch (OOW) operates with short-term memory,
constantly processing ever-changing information about course, rudder, speed, position, and
surrounding vessels, while simultaneously relying on long-term memory to prioritize data that ensures
the ship’s safety in the current situation. This process can feel automatic, akin to walking or eating; it
often occurs unconsciously as our working habit. However, if subconscious thoughts do not surface
correctly, it can lead to feelings of panic, fear, or confusion stemming from uncertainty. This is why the
chapters in this book are arranged in a suspenseful manner. I do not believe anyone can read it once
and fully grasp what they should do while on bridge watch.
Situational awareness has three layers, as defined by the U.S. Navy:
Knowledge: Our senses detect the situation and focus our attention.
Understanding: Our subconscious processes key elements and recognizes when something
is wrong.
Proficiency: Our bodies react according to established procedures, minimizing the risk of
unconscious errors, aligning with the standards set by STCW..
Often, our eyes may see something, but we may not understand its significance—an example of
this is the Sanchi case illustrated in Figure 3-1, which depicts the navigational track of SANCHI and CF
CRYSTAL. Conversely, we may also overlook impending dangers, as seen in the Ever Smart case
shown in Figure 7-09, which depicts the two minutes preceding a collision.
To achieve correct situational awareness, we need proper training that focuses on:
Verifying statements to enhance our attention in short-term memory.
Practicing skills to develop our long-term contextual memory.
Following correct sequences to cultivate our long-term procedural memory.
Figure 11-02 Collision Risk in Point, and Line
Collision definition:A collision occurs when two targets arrive at the same place at the same time,
as illustrated in Figure 11-02. We can define:
Collision Point Risk:This is the point at which the course lines of two vessels intersect,
represented by the yellow circle in the diagram. A collision point riskdoes not imply a collision
has occurred; we must verify its location in their collision line.
Collision Line Risk: The line of two Ship’s 3 minutes speed vectorcrossing each other like the
vessels in Figure 2-15. 3 minutes is the time needed for course altering. Speed
vectorcrossed in this time frame means collision will easily occur due to steering difficulties.
In another words, two vessels arrive same collision point within 3 minutes difference deems
collision risk exist.
Collision AreaRisk:This encompasses the area where the speed vectors of multiple ships
overlap in the last three minutes, as seen in:
Figure 11-03: Matrix of close-crossing vessels outside the harbor
Figure 7-01: Merry-Go-Round of long-distance crossing vessels
Figure 6-06: Long array of outbound vessels
Figure 5-18: Rock the ship inside communist pocket tactics
Figure 3-04: Dual targets crossing case
Figure 2-19: Collision targets merged in radar echo (These drawing number need
to review)
These multiple collision risk areas should be avoided by the OOW(e.g., by going around; if not
possible, calling the master). Conversely, these areas should be navigated by Captain’s skill, who must
find suitable sea room or timing to transit. Vessel concentrations are often temporary; therefore,
reducing speed is always the best remedy when adequate sea room is not available.
Figure 11-03 Collision AreaRisk in Square
The concept of Collision Point Risk: This raises awareness of potential crossing situations.
Many collision points exist near harbor areas (statement serves as common sense).
Not all collision points carry a collision risk (another statement).
Only those points where the own ship arrives at the same time as another vessel present a
collision risk (a further statement).
Collision points enhance awareness of potential crossing situations during voyage planning
(the skill is the need to use our senses to check at least one criterion of concern for safety).
To ascertain collision risk, focus on the end of our speed vector(skill).
The end of another vessel’s speed vectorindicates its position after the time set by our
ARPAsettings (skill).
Figure 11-04 How to read collision point riskfrom vessel’s 6 minutes speed vectors
In Figure 11-04, the speed vectoris set to six minutes. We use longer time settings for speed
vectors to enhance collision awareness if necessary.
No. 1 Collision Point: There is no collision risk with the own ship (red line).
Ownship will reach the collision point in half the time of six minutes.
The target vessel will arrive at the collision point more than five minutes
from now. (estimated from collision point location in its speed vector)
The own ship will pass target vessel's bow after three minutes (this is
the skill in judging the collision point on a six-minute speed vector).
No. 2 Collision Point: Involves uncertain collision risk (sense is skill we have to
practice)
Ownship will reach the collision point in 3.5 minutes (skill: measuring the
collision point distance using the own ship’s speed vector).
The target vessel will reach the collision point at about the same time
(skill: measuring the collision point distance using the target vessel’s
speed vector).
Ownship has a collision risk with this vessel (skill in judging the collision
point on a six-minute speed vector).
No. 3 Collision Point: Also involves uncertain collision risk (sense).
Ownship will reach the collision point in five minutes (measuring the collision point
distance using the own ship’s speed vector).
The collision point is located at the end of the target vessel’s speed
vector(measuring the collision point distance using the target vessel’s speed
vector).
Ownship has a collision risk with this vessel (knowledge as in Figure 2-15
regarding space shipstatus).
Collision risks for No. 2 and No. 3 can potentially be avoided by reducing ownship’s speed.
Figure 11-05 How to read collision line riskfrom vessel’s 3 minutes speed vectors
The concept of Collision Line Risk: This raises awareness of the own ship’s need to alter course
when required by either the own ship or a target vessel (refer to Figure 2-8 for Distance of Advance
requirements).
After checking the collision points in Figure 11-04, let’s use a three-minute speed vectorlength to
verify the situations on the ARPAscreen as shown in Figure 11-05, collision awareness involves:
No. 1 Crossing Vessel: This vessel is slower than ownship in reaching the collision point.
The own ship will pass ahead of her bow (sense).
The green circle covered by No. 1 vessel indicates the area where the No. 1
vessel may be after three minutes (statement).
Regardless of No. 1 vessel's direction, it will not collide with the own ship within
three minutes (statement).
The collision line (three-minute speed vector) does not intersect between the own
ship and No. 1 target.
Therefore, there is no collision risk with No. 1 target in these three minutes (sense
after reducing the speed vector’s length).
If the collision lines (three-minute speed vectors) do not intersect, there is no collision risk
during this timeframe (conclusion).
No. 2 Vessel: Course 160° (T) arrives at the red collision circle almost simultaneously with
the own ship (awareness in Figure 11-05).
This represents the first priority for collision avoidance.
If the course lines of two vessels cross, there exists a collision point risk. However, the crossing of
two vessels' six-minute speed vectors does not necessarily indicate a collision line risk. Conversely,
when two vessels' three-minute speed vectors cross, this signifies a collision line riskdue to the
possibility of collision within the last three minutes, resulting from steering difficulties. Thus, different
speed vectorlengths may be used to enhance collision awareness as needed. (seamanship)
Figure 11-06 How to read collision Arearisk from vessel’s speed vectors
The concept of Collision AreaRisk: The Collision Areais represented by the orange square in
Figure 11-06, indicating a location where seven vessels are expected to arrive simultaneously. In this
scenario, the movement of any one ship interacts immediately with nearby vessels, meaning that each
ship could potentially be both a give-way vesseland a stand-on vesselat the same time.
Precaution:In Collision Area, ownship must consider the dimensions and maneuvering
requirements of other vessels. This aligns with COLREG Rule that states, "A vessel of less
than 20 meters in length or a sailing vessel shall not impede the safe passage of a power
driven vessel following a traffic lane."
Lack of Guidance:The Collision Arearepresents a space where COLREG does not provide
specific guidance to prepare mariners for their ventures. This is illustrated in seamanship
Figure 7-01, which depicts the Merry Roundabout of long-distance crossing vessels.
Understanding Collision Causes:Within the Collision Area, it is imperative for the own ship to
analyze the reasons why collisions occur in this context. This is further explained in
seamanship Figure 5-18.
Application of Knowledge and Skills:In the Collision Area, mariners must utilize their
knowledge, skills, and seamanship within a critical timeframe—often within one minute. This
is exemplified in seamanship Figure 11-03, which depicts Collision AreaRisk in a square.
Collision Awareness Exercise – 01 Safe Speed
##
Motto:Collision risk is proportional to ownship speed. (Truth – Higher speed reduces
reaction time and increases impact severity.)
Objective:Build skills in reading speed vectors, estimating collision time/distance, and
prioritizing risks using radar/ARPA. Focus on mental shortcuts for quick decisions in busy
waters. Use sketches to visualize and discuss.
STM:Short Term Memory (Key Facts to Retain for Quick Recall)
Ownship speed vector: 6-minute length, course 059.5°(T), speed 19.2 knots.
6-minute vectors predict potential collision risks within 6 minutes.
Fishing vessel No. 10 (starboard) has the closest collision point.
It's unclear from the drawing if the two port-side vessels with collision points will arrive
Figure 11-01 Collision Avoidance simulator scene at SGP harbor pilot station
These collision avoidance scenarios are set in the Singapore Strait, just outside the Pilot Eastern
Boarding Ground Alfa, as depicted in Figure 11-01. These exercises are conducted by senior masters
or junior officers of the watch (OOW) from well-known shipping companies. In these exercises,
seniority does not guarantee success; indeed, junior OOWs may adapt to new concepts more rapidly.
Regardless, these exercises provide a valuable opportunity for participants to review their visual and
radar lookout skills without the risks associated with real navigation.
In studies of the human element, real collision avoidance scenarios often generate excessive
mental and physical pressure, which can overload our memory structure. As a result, important
information may be lost for experienced mariners, while those with less experience may struggle to
retain new information.
Regarding instructor briefings before the exercises, some captains can recall the instructions well,
while others cannot. During the exercises, some instructors prefer a hands-off approach, while others
intervene at the first sign of error. Personally, I fall into the latter category; I believe in stopping the
exercise when necessary to gather all bridge personnel and discuss what went wrong and how we can
improve the situation. I recognize that humans operate with limited short-term and long-term memory
regarding procedures. This limitation raises questions about how some individuals ascend to the rank
of Captain. If they lack the correct long-term procedures, any information they absorb from briefings or
lectures will likely remain unreliable, as it may only reside in their short-term memory.
“Steering was never physically lost. Rather, it had been shifted to a different control station, and
the watchstanders failed to recognize this configuration. Compounding the issue, the steering control
transfer to the Lee Helmcaused the rudder to go amidships (centerline). Since the Helmsman had been
steering with 1-4 degrees of right rudder to maintain course before the transfer, the amidships rudder
caused the ship’s course to deviate to the left. Additionally, when the Helmsman reported the loss of
steering, the Commanding Officer slowed the ship to 10 knots and eventually to 5 knots. However, the
Lee Helmsman reduced the speed of only the port shaft, as the throttles were not coupled together
(ganged). The starboard shaft continued at 20 knots for another 68 seconds before its speed was also
reduced. This combination of incorrect rudder direction and the two shafts operating independently led
to an uncommanded turn to the left (port) into a heavily congested traffic area, in close proximity to
three ships, including the ALNIC.
Although the USS JOHN S. MCCAIN was now on a collision course with the ALNIC, the
Commanding Officer and others on the ship’s bridge lost situational awareness. No one on the bridge
clearly understood the forces acting on the ship, nor did they grasp the ALNIC's course and speed
relative to the JOHN S. MCCAIN during the confusion.”
— Report on the Collision between USS JOHN S. MCCAIN and Motor Vessel ALNIC MC,
UNCLASSIFIED.
This incident serves as a poignant reminder of the critical importance of situational awareness and
effective communication in maritime operations.
In the HELM class, I emphasize that the Commanding Officer has only one minute to correct
mistakes. In real scenarios, the Officer of the Watch (OOW) operates with short-term memory,
constantly processing ever-changing information about course, rudder, speed, position, and
surrounding vessels, while simultaneously relying on long-term memory to prioritize data that ensures
the ship’s safety in the current situation. This process can feel automatic, akin to walking or eating; it
often occurs unconsciously as our working habit. However, if subconscious thoughts do not surface
correctly, it can lead to feelings of panic, fear, or confusion stemming from uncertainty. This is why the
chapters in this book are arranged in a suspenseful manner. I do not believe anyone can read it once
and fully grasp what they should do while on bridge watch.
Situational awareness has three layers, as defined by the U.S. Navy:
Knowledge: Our senses detect the situation and focus our attention.
Understanding: Our subconscious processes key elements and recognizes when something
is wrong.
Proficiency: Our bodies react according to established procedures, minimizing the risk of
unconscious errors, aligning with the standards set by STCW..
Often, our eyes may see something, but we may not understand its significance—an example of
this is the Sanchi case illustrated in Figure 3-1, which depicts the navigational track of SANCHI and CF
CRYSTAL. Conversely, we may also overlook impending dangers, as seen in the Ever Smart case
shown in Figure 7-09, which depicts the two minutes preceding a collision.
To achieve correct situational awareness, we need proper training that focuses on:
Verifying statements to enhance our attention in short-term memory.
Practicing skills to develop our long-term contextual memory.
Following correct sequences to cultivate our long-term procedural memory.
Figure 11-02 Collision Risk in Point, and Line
Collision definition:A collision occurs when two targets arrive at the same place at the same time,
as illustrated in Figure 11-02. We can define:
Collision Point Risk:This is the point at which the course lines of two vessels intersect,
represented by the yellow circle in the diagram. A collision point riskdoes not imply a collision
has occurred; we must verify its location in their collision line.
Collision Line Risk: The line of two Ship’s 3 minutes speed vectorcrossing each other like the
vessels in Figure 2-15. 3 minutes is the time needed for course altering. Speed
vectorcrossed in this time frame means collision will easily occur due to steering difficulties.
In another words, two vessels arrive same collision point within 3 minutes difference deems
collision risk exist.
Collision AreaRisk:This encompasses the area where the speed vectors of multiple ships
overlap in the last three minutes, as seen in:
Figure 11-03: Matrix of close-crossing vessels outside the harbor
Figure 7-01: Merry-Go-Round of long-distance crossing vessels
Figure 6-06: Long array of outbound vessels
Figure 5-18: Rock the ship inside communist pocket tactics
Figure 3-04: Dual targets crossing case
Figure 2-19: Collision targets merged in radar echo (These drawing number need
to review)
These multiple collision risk areas should be avoided by the OOW(e.g., by going around; if not
possible, calling the master). Conversely, these areas should be navigated by Captain’s skill, who must
find suitable sea room or timing to transit. Vessel concentrations are often temporary; therefore,
reducing speed is always the best remedy when adequate sea room is not available.
Figure 11-03 Collision AreaRisk in Square
The concept of Collision Point Risk: This raises awareness of potential crossing situations.
Many collision points exist near harbor areas (statement serves as common sense).
Not all collision points carry a collision risk (another statement).
Only those points where the own ship arrives at the same time as another vessel present a
collision risk (a further statement).
Collision points enhance awareness of potential crossing situations during voyage planning
(the skill is the need to use our senses to check at least one criterion of concern for safety).
To ascertain collision risk, focus on the end of our speed vector(skill).
The end of another vessel’s speed vectorindicates its position after the time set by our
ARPAsettings (skill).
Figure 11-04 How to read collision point riskfrom vessel’s 6 minutes speed vectors
In Figure 11-04, the speed vectoris set to six minutes. We use longer time settings for speed
vectors to enhance collision awareness if necessary.
No. 1 Collision Point: There is no collision risk with the own ship (red line).
Ownship will reach the collision point in half the time of six minutes.
The target vessel will arrive at the collision point more than five minutes
from now. (estimated from collision point location in its speed vector)
The own ship will pass target vessel's bow after three minutes (this is
the skill in judging the collision point on a six-minute speed vector).
No. 2 Collision Point: Involves uncertain collision risk (sense is skill we have to
practice)
Ownship will reach the collision point in 3.5 minutes (skill: measuring the
collision point distance using the own ship’s speed vector).
The target vessel will reach the collision point at about the same time
(skill: measuring the collision point distance using the target vessel’s
speed vector).
Ownship has a collision risk with this vessel (skill in judging the collision
point on a six-minute speed vector).
No. 3 Collision Point: Also involves uncertain collision risk (sense).
Ownship will reach the collision point in five minutes (measuring the collision point
distance using the own ship’s speed vector).
The collision point is located at the end of the target vessel’s speed
vector(measuring the collision point distance using the target vessel’s speed
vector).
Ownship has a collision risk with this vessel (knowledge as in Figure 2-15
regarding space shipstatus).
Collision risks for No. 2 and No. 3 can potentially be avoided by reducing ownship’s speed.
Figure 11-05 How to read collision line riskfrom vessel’s 3 minutes speed vectors
The concept of Collision Line Risk: This raises awareness of the own ship’s need to alter course
when required by either the own ship or a target vessel (refer to Figure 2-8 for Distance of Advance
requirements).
After checking the collision points in Figure 11-04, let’s use a three-minute speed vectorlength to
verify the situations on the ARPAscreen as shown in Figure 11-05, collision awareness involves:
No. 1 Crossing Vessel: This vessel is slower than ownship in reaching the collision point.
The own ship will pass ahead of her bow (sense).
The green circle covered by No. 1 vessel indicates the area where the No. 1
vessel may be after three minutes (statement).
Regardless of No. 1 vessel's direction, it will not collide with the own ship within
three minutes (statement).
The collision line (three-minute speed vector) does not intersect between the own
ship and No. 1 target.
Therefore, there is no collision risk with No. 1 target in these three minutes (sense
after reducing the speed vector’s length).
If the collision lines (three-minute speed vectors) do not intersect, there is no collision risk
during this timeframe (conclusion).
No. 2 Vessel: Course 160° (T) arrives at the red collision circle almost simultaneously with
the own ship (awareness in Figure 11-05).
This represents the first priority for collision avoidance.
If the course lines of two vessels cross, there exists a collision point risk. However, the crossing of
two vessels' six-minute speed vectors does not necessarily indicate a collision line risk. Conversely,
when two vessels' three-minute speed vectors cross, this signifies a collision line riskdue to the
possibility of collision within the last three minutes, resulting from steering difficulties. Thus, different
speed vectorlengths may be used to enhance collision awareness as needed. (seamanship)
Figure 11-06 How to read collision Arearisk from vessel’s speed vectors
The concept of Collision AreaRisk: The Collision Areais represented by the orange square in
Figure 11-06, indicating a location where seven vessels are expected to arrive simultaneously. In this
scenario, the movement of any one ship interacts immediately with nearby vessels, meaning that each
ship could potentially be both a give-way vesseland a stand-on vesselat the same time.
Precaution:In Collision Area, ownship must consider the dimensions and maneuvering
requirements of other vessels. This aligns with COLREG Rule that states, "A vessel of less
than 20 meters in length or a sailing vessel shall not impede the safe passage of a power
driven vessel following a traffic lane."
Lack of Guidance:The Collision Arearepresents a space where COLREG does not provide
specific guidance to prepare mariners for their ventures. This is illustrated in seamanship
Figure 7-01, which depicts the Merry Roundabout of long-distance crossing vessels.
Understanding Collision Causes:Within the Collision Area, it is imperative for the own ship to
analyze the reasons why collisions occur in this context. This is further explained in
seamanship Figure 5-18.
Application of Knowledge and Skills:In the Collision Area, mariners must utilize their
knowledge, skills, and seamanship within a critical timeframe—often within one minute. This
is exemplified in seamanship Figure 11-03, which depicts Collision AreaRisk in a square.
Collision Awareness Exercise – 01 Safe Speed
##
Motto:Collision risk is proportional to ownship speed. (Truth – Higher speed reduces
reaction time and increases impact severity.)
Objective:Build skills in reading speed vectors, estimating collision time/distance, and
prioritizing risks using radar/ARPA. Focus on mental shortcuts for quick decisions in busy
waters. Use sketches to visualize and discuss.
STM:Short Term Memory (Key Facts to Retain for Quick Recall)
Ownship speed vector: 6-minute length, course 059.5°(T), speed 19.2 knots.
6-minute vectors predict potential collision risks within 6 minutes.
Fishing vessel No. 10 (starboard) has the closest collision point.
It's unclear from the drawing if the two port-side vessels with collision points will arrive
