Chapter 9: Situational Awareness for Master

Collision Awareness Exercise – 11 Visual Lookout

​​​The motto: Your time in visual lookout depends on ARPA skill 

Figure 9-01 Ownship speed vector in 3 and 6 minutes at beginning 

The situational awareness is:

1. 1.      With three minutes speed vector Course 065⁰(T), speed 21 Knots, vector length is about 10.5 cables as above. 
2. 2.      Ownship have three crossing vessels at starboard side, distance unknown. 

After Ownship adjust speed vectors to 6 minutes length we found a collision area risk. 

Figure 9-02 Ownship speed vector in 3 and 6 minutes at one minute time 

After 01minutes exercise time lapsed:

1. 1.     Ownship speed is 18.4 knots which had reduced from 21 kts by reduce Engine Revolution to 16%. Although the engine telegraph setting is 16%, propeller revolution is reduced very slowly. This is due to propeller submerged in the water. Vessel proceeds with 21 knots before with great momentum which push vessel forward continuously.   
2. 2.     Ownship course is steady on 065 degrees after one minute. ​

The situational awareness is 

• First crossing vessel will be about ownship bow after three minutes. (sighted)
• Two other crossing vessels are unknown with three minutes speed vector. (sighted)
• ​​​​​​​The situational awareness with 6 minutes speed vector is Ownship have collision risk with two starboard side crossing vessel after 6 minutes, some vessels earlier and some later in one collision area. (sighted with 6 minutes speed vector)
• Safe position is more important than safe speed. (rule in this area)
• Ownship had not taken any action to avoid the collision risk square. (sighted no course alternation in this minute)

Figure 9-03 Ownship speed vector in 3 and 6 minutes at 2 minutes time 

After 02minutes exercise time lapsed:

1. 1.     Ownship speed is 16.4 knots which had reduced from 18.4 kts even engine output is increased to 48% at 01 minute 30 seconds. 
2. 2.     Ownship course is changing 065 to 067.8 degrees after one minute 30 second with “Hard Starboard” rudder. ​

The situational awareness is 

• first crossing vessel will be about ownship bow after 3 minutes. (sighted)
• Two other crossing vessels are unknown with 3 minutes speed vector. (sighted)​​​​​​​
• The situational awareness after 6 minutes is:
• Ownship have collision risk with one starboard side crossing vessel (in pink circle) after 5 minutes. (sighted with 6 minutes speed vector)
• Another crossing vessel will pass ownship bow after 4 minutes. (skill as below)
• By verifying collision point (red circle on speed vector) position, red line length is about one third of her three minutes speed vector. (By using finger span to compare is Good, have a divider beside ARPA is recommended)

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Figure 9-04 Ownship speed vector in 3 minutes at 3 and 4 minutes time 

After 03minutes exercise time lapsed:

1. 1.     Ownship speed is 17.2 knots which had increased from 16.4, with engine output increased again to 90% at 02 minute 30 seconds. 
2. 2.     Ownship course is changing from 065 to 076.3 (T) using 30 seconds varied “Starboard” rudder. ​ Rudder order “Starboard 15” once again after 2 minutes 30 seconds.
3. 3.     Second crossing vessel had altered course to port side, course unknow but speed vector is clear of collision point.

The situational awareness is 

• Three crossing vessels should be OK in this heading 076⁰(T) judging by speed vectors. (sighted)
• First crossing vessel has collision point but the passing time at ownship’s bow is very short. (sighted) 
• Second starboard side crossing vessel had altered course to port side already, her course unknow. (sighted by visual or speed vector’s direction or course reading in ARPA)
• Verify target’s position (is it inside TSS?) before give way action is important. (she may not come inside TSS)
• Verify target’s type (supply vessels or fishing vessels) before give way action is important. (she may not come inside TSS)
• Monitor target’s course constantly by visual is important. (collision risk changes if she alters course)
• Visual is the most effective way to monitor target’s course change as no time lag like speed vector. (sense)
• How many times you can spend in monitoring target vessel course visually depends on your skill level in radar lookout. (sense)
• Ownship Increase speed to increase rudder effect or give way to overtaken vessel or worry about fast overtaking vessel astern. (suspect)

Ownship is safe in this course and speed, only captain don’t know this situation. After 04 minutes exercise time lapsed:

1. 1.     Ownship speed is 16.1 knots which had changed from 17.2, 16.4, 18.4 kts with engine output is decreased third time to 59% from 90% at 02 minute 30 seconds. 
2. 2.     Ownship course is changing to 086 degrees from 076.3 degrees. “Starboard” rudder using is effective and “Port”rudder responding is slow.  ​ Rudder order “Hard Port” now to steady the vessel.

The situational awareness is 

• Two crossing vessels passed ownship bow. (sighted)
• Second crossing vessel is at starboard bow almost end-on. (ownship had caused confuse at sea)
• This vessel should be OK if ownship can notice her course change immediately when turning. (skill) 
• Even ownship is altering course captain should look outside the window to know other ship’s movement. (prudent navigator)
• Speed reduced for ownship is gain some extra time to evaluate. (suspect)
• Or ownship want to pass fast overtaking bow. (suspect)

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Figure 9-05 Ownship speed vector in 3 minutes at 5 minutes time 

After 05minutes exercise time lapsed:

1. 1.     Ownship speed is 15.3 knots which had changed from 16.1, 17.2, 16.4, 18.4 kts with engine output 59% from 02 minute 30 seconds. 
2. 2.     Ownship course is steady in 086 degrees from 065, 076.3 degrees. 

The situational awareness is 

• “Starboard” rudder (Lower Square) is more effective than “Port” rudder (Upper Square). (sighted) 
• This awareness should be ready when OOW or Captain first report to bridge by checking which side is windward. (force majeure)
• Two crossing vessels passed ownship bow. (sighted)
• One crossing vessel at starboard bow had altered course to port side. (sighted)
• Speed reduced slowly. ownship is not worry about overtaken vessel abeam. (suspect)
• Ownship had passed fast overtaking bow. (suspect)

​​​​​​​ Verify target’s position and type before give way action

Collision Awareness Exercise – 12 Observing the collision point

​​​The motto: How to mark 3 minutes run in speed vector?

Refer to figure 9-01, the initial situational awareness is:

1. 1.     With three minutes speed vector Course 065⁰(T), speed 21 Knots, vector length is about 10.5 cables as above. 
2. 2.     Ownship have three crossing vessels at starboard side, distance unknown.