首頁 ﹥ 商品介紹 > BRM for 21 century > Knowledge Base and Situation Awarenese for Master > Chapter 11 Dynamic Navigation for Master
Chapter 11 Dynamic Navigation for Master
以下是該段文字的繁體中文翻譯：
第 11 章：船長的動態航行（Dynamic Navigation for Master）
圖 11-01 新加坡港引水站的避碰模擬器場景
這些避碰演練場景設定於新加坡海峽、東部甲類引水登船區（Pilot Eastern Boarding Ground Alfa）外圍，如圖 11-01 所示。演練對象為來自知名航商的高級船長或初級值班船員（OOW）。在這些演練中，資歷並不保證成功；事實上，初級 OOW 反而可能更快適應新觀念。無論如何，這些演練為參演人員提供了一個寶貴的機會，可在不承擔真實航行風險的情況下，審視並檢討其視覺與雷達瞭望技能。
在人為因素（Human Element）的研究中，真實的避碰場景常會產生過度的心理與生理壓力，進而使我們的記憶結構過載。結果導致經驗豐富的航海人員可能會遺漏重要資訊，而經驗較淺者則可能難以吸收與吸收新資訊。
關於演練前指導員簡報的部分，有些船長能很好地記住指示，有些則不然。演練期間，有些指導員偏好採取不干涉態度，有些則在出現錯誤跡象時便立即介入。就個人而言，我屬於後者；我主張在必要時暫停演練，召集所有駕駛台人員討論問題所在以及如何改善狀況。我深知人類在面對作業程序時，其短期與長期記憶皆有所局限。這種局限性引發了一個疑問：部分人員究竟是如何晉升至船長職位的？若他們缺乏正確的長期程序記憶，從簡報或講座中所吸收的任何資訊都可能不可靠，因為這些資訊可能僅停留在他們的短期記憶中。
「操舵系統從未在物理層面上失靈，而是被切換到了不同的控制站，但值班人員並未察覺此一配置。更嚴重的是，將操舵控制轉移至副操舵手（Lee Helm）時，導致舵角回中（位於中線）。由於在切換前，操舵手一直保持右舵 1 至 4 度以維持航向，因此舵角回中導致船隻航向向左偏離。此外，當操舵手回報失去操舵能力時，艦長將船速減至 10 節，隨後進一步減至 5 節。然而，副操舵手僅降低了左軸的轉速，因為雙軸節流閥並未併聯（Ganged）。右軸在接下來的 68 秒內仍以 20 節的速度運轉，之後轉速才被降低。這種錯誤的舵向與雙軸獨立運轉的組合，導致船隻在接近包含 ALNIC 號在內的三艘船隻的擁擠航道中，非指令性地向左（左舷）急轉。
儘管 USS JOHN S. MCCAIN 號當時已與 ALNIC 號處於碰撞航向上，艦長與駕駛台上的其他人員卻失去了情境意識（Situational Awareness）。在混亂中，駕駛台上沒有人清楚了解作用於船隻上的外力，亦未能掌握 ALNIC 號相對於 JOHN S. MCCAIN 號的航向與航速。」
—— 《USS JOHN S. MCCAIN 號與機動船 ALNIC MC 號碰撞事件報告》（未定密）
此事件嚴正提醒了我們，情境意識與有效溝通在海上作業中具有至關重要的權重。
在 HELM（駕駛台資源管理與人為因素）課程中，我強調艦長/船長只有一分鐘的時間來糾正錯誤。在真實場景中，值班船員（OOW）依賴短期記憶，持續處理關於航向、舵角、船速、位置及周圍船隻等瞬息萬變的資訊，同時須依賴長期記憶來排定資料的優先順序，以確保船舶在當前狀況下的安全。這個過程感覺就像走路或進食一樣自動化；它常作為我們的習慣而潛意識地發生。然而，若潛意識未能正確浮現，不確定性便可能引發恐慌、恐懼或困惑。這也是本書各章節以懸疑方式編排的原因。我不相信有人只需閱讀一次，就能完全掌握在駕駛台值班時應採取的所有行動。
根據美國海軍的定義，情境意識（Situational Awareness）分為三個層次：
認知（Knowledge）： 我們的感官察覺到狀況，並集中我們的注意力。
理解（Understanding）： 我們的潛意識處理關鍵要素，並在出現異常時即時識別。
精通（Proficiency）： 我們的身體根據既定程序做出反應，將無意識錯誤的風險降至最低，符合 STCW 標準。
通常，我們的眼睛可能看到了某個現象，卻無法理解其重要性——圖 3-1 所示的桑吉號（SANCHI）案例即是一例，該圖描繪了桑吉號與長峰水晶號（CF CRYSTAL）的航跡。相反地，我們也可能忽視即將到來的危險，如圖 7-09 所示的 Ever Smart 號案例，該圖描繪了碰撞前兩分鐘的情況。
要獲得正確的情境意識，我們需要進行針對以下重點的適當訓練：
驗證陳述，以增強短期記憶中的注意力。
練習技能，以發展長期情境記憶（Long-term contextual memory）。
遵循正確順序，以養成長期程序記憶（Long-term procedural memory）。
圖 11-02 點與線的碰撞風險
碰撞定義： 當兩個目標在同一時間到達同一地點時，即發生碰撞，如圖 11-02 所示。我們可以定義：
碰撞點風險（Collision Point Risk）： 這是兩艘船隻航向線相交的點，在圖中以黃色圓圈表示。碰撞點風險並不意味著已經發生碰撞；我們必須在其碰撞線上驗證其位置。
碰撞線風險（Collision Line Risk）： 兩船 3 分鐘速度向量相交的線，類似圖 2-15 中的船隻。3 分鐘是轉向所需的時間。在此時間範圍內速度向量相交，意味著由於操舵困難，極易發生碰撞。換句話說，兩艘船隻在 3 分鐘的時間差內到達同一個碰撞點，即視為存在碰撞風險。
碰撞區風險（Collision Area Risk）： 這涵蓋了多艘船隻的速度向量在最後 3 分鐘內重疊的區域，如以下所示：
圖 11-03：港外近距離交叉船隻矩陣
圖 7-01：遠距離交叉船隻的旋轉木馬效應
圖 6-06：出港船隻長縱隊
圖 5-18：共產黨口袋戰術中的搖晃船舶
圖 3-04：雙目標交叉案例
图 2-19：雷達回波中合併的碰撞目標（這些圖號需要重新審視）
這些多重碰撞風險區域應由 OOW 予以避開（例如：繞道而行；若無法避開，則呼叫船長）。相反地，這些區域應由船長憑藉專業技能進行航行，船長必須找到合適的海域空間或時機通過。船舶聚集通常是暫時的；因此，在沒有足夠海域空間時，減速永遠是最好的補救措施。
圖 11-03 方格中的碰撞區風險
碰撞點風險的概念： 這能提高對潛在交叉狀況的警覺。
港口附近存在許多碰撞點（此陳述屬於常識）。
並非所有碰撞點都帶有碰撞風險（另一個陳述）。
只有當本船與另一艘船隻同時到達該點時，才會產生碰撞風險（進一步的陳述）。
碰撞點可在航程計畫期間提高對潛在交叉狀況的警覺（這項技能需要利用我們的感官檢查至少一項安全關切基準）。
要確定碰撞風險，應專注於我們速度向量的末端（技能）。
另一艘船隻速度向量的末端，代表其在我們 ARPA 設定時間後的預測位置（技能）。
圖 11-04 如何從船隻 6 分鐘速度向量判讀碰撞點風險
在圖 11-04 中，速度向量設定為 6 分鐘。必要時，我們會使用較長的速度向量時間設定來增強碰撞警覺。
1號碰撞點： 與本船（紅線）無碰撞風險。
本船將在 6 分鐘的一半時間（即 3 分鐘）內到達碰撞點。
目標船隻將在距今 5 分鐘以上才到達碰撞點（根據其速度向量上的碰撞點位置估算）。
本船將在 3 分鐘後駛過目標船隻的船首（這是根據 6 分鐘速度向量判斷碰撞點的技能）。
2號碰撞點： 包含不確定的碰撞風險（直覺是我們必須練習的技能）。
本船將在 3.5 分鐘內到達碰撞點（技能：利用本船速度向量測量碰撞點距離）。
目標船隻也將在大致相同的時間到達碰撞點（技能：利用目標船隻速度向量測量碰撞點距離）。
本船與該船存在碰撞風險（根據 6 分鐘速度向量判斷碰撞點的技能）。
3號碰撞點： 同樣包含不確定的碰撞風險（直覺）。
本船將在 5 分鐘內到達碰撞點（利用本船速度向量測量碰撞點距離）。
碰撞點位於目標船隻速度向量的末端（利用目標船隻速度向量測量碰撞點距離）。
本船與該船存在碰撞風險（如圖 2-15 關於太空船狀態的知識）。
針對 2 號和 3 號碰撞點的風險，潛在的避讓方式為降低本船航速。
第 11 章：船長的動態航行（Dynamic Navigation for Master）
圖 11-01 新加坡港引水站的避碰模擬器場景
這些避碰演練場景設定於新加坡海峽、東部甲類引水登船區（Pilot Eastern Boarding Ground Alfa）外圍，如圖 11-01 所示。演練對象為來自知名航商的高級船長或初級值班船員（OOW）。在這些演練中，資歷並不保證成功；事實上，初級 OOW 反而可能更快適應新觀念。無論如何，這些演練為參演人員提供了一個寶貴的機會，可在不承擔真實航行風險的情況下，審視並檢討其視覺與雷達瞭望技能。
在人為因素（Human Element）的研究中，真實的避碰場景常會產生過度的心理與生理壓力，進而使我們的記憶結構過載。結果導致經驗豐富的航海人員可能會遺漏重要資訊，而經驗較淺者則可能難以吸收與吸收新資訊。
關於演練前指導員簡報的部分，有些船長能很好地記住指示，有些則不然。演練期間，有些指導員偏好採取不干涉態度，有些則在出現錯誤跡象時便立即介入。就個人而言，我屬於後者；我主張在必要時暫停演練，召集所有駕駛台人員討論問題所在以及如何改善狀況。我深知人類在面對作業程序時，其短期與長期記憶皆有所局限。這種局限性引發了一個疑問：部分人員究竟是如何晉升至船長職位的？若他們缺乏正確的長期程序記憶，從簡報或講座中所吸收的任何資訊都可能不可靠，因為這些資訊可能僅停留在他們的短期記憶中。
「操舵系統從未在物理層面上失靈，而是被切換到了不同的控制站，但值班人員並未察覺此一配置。更嚴重的是，將操舵控制轉移至副操舵手（Lee Helm）時，導致舵角回中（位於中線）。由於在切換前，操舵手一直保持右舵 1 至 4 度以維持航向，因此舵角回中導致船隻航向向左偏離。此外，當操舵手回報失去操舵能力時，艦長將船速減至 10 節，隨後進一步減至 5 節。然而，副操舵手僅降低了左軸的轉速，因為雙軸節流閥並未併聯（Ganged）。右軸在接下來的 68 秒內仍以 20 節的速度運轉，之後轉速才被降低。這種錯誤的舵向與雙軸獨立運轉的組合，導致船隻在接近包含 ALNIC 號在內的三艘船隻的擁擠航道中，非指令性地向左（左舷）急轉。
儘管 USS JOHN S. MCCAIN 號當時已與 ALNIC 號處於碰撞航向上，艦長與駕駛台上的其他人員卻失去了情境意識（Situational Awareness）。在混亂中，駕駛台上沒有人清楚了解作用於船隻上的外力，亦未能掌握 ALNIC 號相對於 JOHN S. MCCAIN 號的航向與航速。」
—— 《USS JOHN S. MCCAIN 號與機動船 ALNIC MC 號碰撞事件報告》（未定密）
此事件嚴正提醒了我們，情境意識與有效溝通在海上作業中具有至關重要的權重。
在 HELM（駕駛台資源管理與人為因素）課程中，我強調艦長/船長只有一分鐘的時間來糾正錯誤。在真實場景中，值班船員（OOW）依賴短期記憶，持續處理關於航向、舵角、船速、位置及周圍船隻等瞬息萬變的資訊，同時須依賴長期記憶來排定資料的優先順序，以確保船舶在當前狀況下的安全。這個過程感覺就像走路或進食一樣自動化；它常作為我們的習慣而潛意識地發生。然而，若潛意識未能正確浮現，不確定性便可能引發恐慌、恐懼或困惑。這也是本書各章節以懸疑方式編排的原因。我不相信有人只需閱讀一次，就能完全掌握在駕駛台值班時應採取的所有行動。
根據美國海軍的定義，情境意識（Situational Awareness）分為三個層次：
認知（Knowledge）： 我們的感官察覺到狀況，並集中我們的注意力。
理解（Understanding）： 我們的潛意識處理關鍵要素，並在出現異常時即時識別。
精通（Proficiency）： 我們的身體根據既定程序做出反應，將無意識錯誤的風險降至最低，符合 STCW 標準。
通常，我們的眼睛可能看到了某個現象，卻無法理解其重要性——圖 3-1 所示的桑吉號（SANCHI）案例即是一例，該圖描繪了桑吉號與長峰水晶號（CF CRYSTAL）的航跡。相反地，我們也可能忽視即將到來的危險，如圖 7-09 所示的 Ever Smart 號案例，該圖描繪了碰撞前兩分鐘的情況。
要獲得正確的情境意識，我們需要進行針對以下重點的適當訓練：
驗證陳述，以增強短期記憶中的注意力。
練習技能，以發展長期情境記憶（Long-term contextual memory）。
遵循正確順序，以養成長期程序記憶（Long-term procedural memory）。
圖 11-02 點與線的碰撞風險
碰撞定義： 當兩個目標在同一時間到達同一地點時，即發生碰撞，如圖 11-02 所示。我們可以定義：
碰撞點風險（Collision Point Risk）： 這是兩艘船隻航向線相交的點，在圖中以黃色圓圈表示。碰撞點風險並不意味著已經發生碰撞；我們必須在其碰撞線上驗證其位置。
碰撞線風險（Collision Line Risk）： 兩船 3 分鐘速度向量相交的線，類似圖 2-15 中的船隻。3 分鐘是轉向所需的時間。在此時間範圍內速度向量相交，意味著由於操舵困難，極易發生碰撞。換句話說，兩艘船隻在 3 分鐘的時間差內到達同一個碰撞點，即視為存在碰撞風險。
碰撞區風險（Collision Area Risk）： 這涵蓋了多艘船隻的速度向量在最後 3 分鐘內重疊的區域，如以下所示：
圖 11-03：港外近距離交叉船隻矩陣
圖 7-01：遠距離交叉船隻的旋轉木馬效應
圖 6-06：出港船隻長縱隊
圖 5-18：共產黨口袋戰術中的搖晃船舶
圖 3-04：雙目標交叉案例
图 2-19：雷達回波中合併的碰撞目標（這些圖號需要重新審視）
這些多重碰撞風險區域應由 OOW 予以避開（例如：繞道而行；若無法避開，則呼叫船長）。相反地，這些區域應由船長憑藉專業技能進行航行，船長必須找到合適的海域空間或時機通過。船舶聚集通常是暫時的；因此，在沒有足夠海域空間時，減速永遠是最好的補救措施。
圖 11-03 方格中的碰撞區風險
碰撞點風險的概念： 這能提高對潛在交叉狀況的警覺。
港口附近存在許多碰撞點（此陳述屬於常識）。
並非所有碰撞點都帶有碰撞風險（另一個陳述）。
只有當本船與另一艘船隻同時到達該點時，才會產生碰撞風險（進一步的陳述）。
碰撞點可在航程計畫期間提高對潛在交叉狀況的警覺（這項技能需要利用我們的感官檢查至少一項安全關切基準）。
要確定碰撞風險，應專注於我們速度向量的末端（技能）。
另一艘船隻速度向量的末端，代表其在我們 ARPA 設定時間後的預測位置（技能）。
圖 11-04 如何從船隻 6 分鐘速度向量判讀碰撞點風險
在圖 11-04 中，速度向量設定為 6 分鐘。必要時，我們會使用較長的速度向量時間設定來增強碰撞警覺。
1號碰撞點： 與本船（紅線）無碰撞風險。
本船將在 6 分鐘的一半時間（即 3 分鐘）內到達碰撞點。
目標船隻將在距今 5 分鐘以上才到達碰撞點（根據其速度向量上的碰撞點位置估算）。
本船將在 3 分鐘後駛過目標船隻的船首（這是根據 6 分鐘速度向量判斷碰撞點的技能）。
2號碰撞點： 包含不確定的碰撞風險（直覺是我們必須練習的技能）。
本船將在 3.5 分鐘內到達碰撞點（技能：利用本船速度向量測量碰撞點距離）。
目標船隻也將在大致相同的時間到達碰撞點（技能：利用目標船隻速度向量測量碰撞點距離）。
本船與該船存在碰撞風險（根據 6 分鐘速度向量判斷碰撞點的技能）。
3號碰撞點： 同樣包含不確定的碰撞風險（直覺）。
本船將在 5 分鐘內到達碰撞點（利用本船速度向量測量碰撞點距離）。
碰撞點位於目標船隻速度向量的末端（利用目標船隻速度向量測量碰撞點距離）。
本船與該船存在碰撞風險（如圖 2-15 關於太空船狀態的知識）。
針對 2 號和 3 號碰撞點的風險，潛在的避讓方式為降低本船航速。
售價 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
