Chapter 2: Knowledge Base for Junior Officer

A junior officer at sea is differ from rating by his competence license of OOW which is an honor by the STCW compliance in international standard.  In the real world we see these OOW as bunch of foolish young man who have the license to use Radar, ARPA, ECDIS etc., but not really understand what potential danger incorporated in it. Company and school had reminded them what danger should be carefully taken care. No one knows what their real reaction will be when the situation rises. Knowledge awareness for Junior Officer are basically those common scenes we sought at instruments at bridge which we categorized those into useful hints for situational awareness. 

Knowledge Base for Junior Officer

Figure 2-1 First Watch: Vessel just sailed out of home port

You are a new OOW on board. Vessel just sailed out of home port. Luckily, the traffic is not heavy outside. Your hands are on Radar tried to familiar with VRM (Variable Rang Mark) and EBL (Electrical Bearing Line) Track ball usage. How to arrange speed vector and trail length? This old man stands before the window beside bridge door asked “Sir, there is a vessel crossing in port side”. “Oh! OK! Let me check” you said. “No, no, Sir, I’m sure” he resumed. Oh! Hell! What’s the rush? How can you an AB so sure about it? But, you did not say. You are a rookie and you don’t know nothing yet. What’s wrong from here?  

Visual lookout is first and last thing at bridge.

We should look out the bridge window first. What to look at is the lesson you had to learn while you are a cadet officer on bridge before you got this COC certificate of competence of OOW. First thing is to search the clues of their distance to us. In portside, I sought the reflection and wake current and few lights of relatively small vessel compared with our containers on board, Figure 2-1.  There are four vessels visible on portside now. Fifth one in starboard side three or two miles range with one light only. How can I know their distance and their aspect (which side is facing ownship)?  What to do about these vessels? Should I use the binocular now?

Fifth one in starboard side: One light maybe is a stern light of big vessel or masthead light of a small vessel? Her water line is very close to ownship’s blind area: SOLAS chapter V REGULATION 22 - Navigation bridge visibility

The view of the sea surface from the conning position shall not be obscured by more than two ship lengths, or 500 m, whichever is the less.

Let’s draw an invisible horizon according to SOLAS visibility requirement: 500 meters from bridge conning position, Figure 2-2. Starboard side vessel is ahead of this horizon. No matter it is a big vessel or small vessel, those two vessels on portside are on the line which are clear indication of their distance are 500 meters from ownship’s bridge together with their deck lights and reflection and glare on white light.  How to set the priority to access collision risk of these two vessels?

Figure 2-2 Determine target vessel distance by SOLAS regulation of Visibility  

The one has small relative bearing (bearing measured from our fore mast to target) should has first priority.  It is human nature but a knowledge for young man. What is Tunnel Effect: The phenomenon by which all surroundings seem to be concentrated at one point at the horizon and sees only the objects right in front of the eyes, this effect results in less perception of the things on the sides of the fairway. It starts ignoring peripheral targets in order to focus on forward one. The target forward has higher relative speed if both vessels in reciprocal course as Head-on situation in COLREG:Rule 14

 (a). When two power-driven vessels are meeting on reciprocal or nearly reciprocal courses so as to involve risk of collision.

(b). Such a situation shall be deemed to exist when a vessel sees the other ahead or nearly ahead.

Head-on rule said: when you see the other ahead or nearly ahead such a situation (meeting on reciprocal courses so as to involve risk of collision) shall be deemed to exist. In the same rule (b) said: 

by night she could see the masthead lights of the other in a line or nearly in a line and/or both sidelights and by day she observes the corresponding aspect of the other vessel.  

Figure 2-3 we set number one priority to the target vessel at port side but this vessel is not head-on situation as she is not seen at ahead of ownship. Usually vessels relative bearing over 10 degrees to both side of ownship’s fore mast are not deemed as head-on situation considering tunnel effect.  Outside this bearing sector even two vessels have reciprocal courses it will not have collision risk. The reason will left for senior OOW to study in next chapter. But the relative speed of crossing vessel No.1 is still very high compared with crossing target vessel number 2 at portside.    

Figure 2-3 See another vessel ahead or nearly ahead?

Head-on situation in COLREG: Rule 14

by night she could see the masthead lights of the other in a line or nearly in a line and/or both sidelights and by day she observes the corresponding aspect of the other vessel.  

Look at Figure 2.3. Mama mia. Give me a break. Who can tell what lights this no. 1 target vessel are displayed? Once there is a motto or standing order: If you cannot make sure what direction target vessel is going? Do not take any action to avoid. How can I make sure this vessel’s heading by her lights on board?  By using binocular, we still cannot know where her bow or stern is located. We should use target’s bearing change to estimate her movement. Trying to figure out what side this small vessel is facing us? Sometimes, it is a waste of time like no.1 target at Figure 2-3 in this range. The time is precious due to close range.  How can I make sure this vessel’s bearing change? Using compass bearing we need a gyro repeater properly adjusted and azimuth circle and may lost our night vision to read the bearing of gyro compass. Our eye’s adaptation to darkness need 5 to 10 minutes. If we don’t want to lost our night vision, stand where you are and use your line of sight to check her bearing change. However, I did not prepare line of sight in Figure 2-4. After all, your eyes need some exercise. I leave some clues on the picture but you should not use. Use what we teaching in chapter one to create line of sight. 

In summary, Target No.1 and 3 bearing changed about the same rate which should be OK to pass. Target No.2 and 4 bearing changed slow but acceptable for her is moving in same direction as ownship.  But, we do have the problem with the white light on our starboard side. She is about 500 meters ahead of ownship’s bow by visibility rule. How we should arrange our priority of lookout now? Or should we take action now?

Figure 2-4 what did you see about target vessel movement?

Bearing changed slow, acceptable or not

We are lucky here. Did you know? These targets are small vessel they did not growing bigger and bigger as a monster ship.  Let’s take a look at Figure 2-5 No.1 target had bearing change about 6 degrees in ownship port side. Her original distance to ownship is about 1026 meters. This distance 1026 meters multiple with 6 degrees bearing change can create 107 meters beam distance. 

1026 x Sin ( 6⁰) = 107 meters (from white spot moving to current ship’s position). 

This 107 meters is a more than two times of her ship’s length (about 30 meters) which is enough for her to pass clear. Her distance 1026 meters are derived from ahead distance 500 meters + 200 meters from bridge to ownship bow= 700 meters ahead of bridge. Ahead distance multiple by Cosine 47 degrees,  700 x cos(47)= 1026 meters.  1026 meters are 5.5 cable about half nautical mile. As the calculation here, should we memorize as follow:

For small vessel less than 30 meters long and the distance is half nautical mile away, 6 degrees bearing change will be enough to clear. Actually, this is not the case. No.1 target is moving away from original relative position to our portside direction. So the rule for passing safely should be: 

Portside vessel moving to portside with 6 degrees bearing change in half nautical mile distance away.  

In another words, portside vessel moving to starboard side is not safe which means this target is sailing toward ownship trying to cross ownship’s bow. In chapter one we said passing vessel’s aspect is important. If their port side facing ownship’s port side is safe, port to port. In small vessel their moving is important. If they are moving to port side in ownship’s port side is safe, port to port. The difference in judging the safety of big vessel by which side they are facing ownship and small vessel by which way they are going is because: we cannot make sure what small vessel’s formation or construction of their navigation/working lights?   

Take a look of target no.2. we cannot say what light is this or that? But we can say she is going the same direction as ownship. That will be enough. We did not break the first rule of lookout. Make sure you know where she is going. 

Figure 2-5 what did you see about target bearing change?

For target vessel on ownship’s starboard side, we observed from red line of sight: her bearing change are about three degrees only together with obvious reflection on sea and augment of her light’s glare now. These all make us feel a sense of danger. Maybe she is closing in portside from starboard? Or her beam distance is not enough? Or she is overtaken by ownship in close range?  A starboard side vessel is closing to ownship is for sure? And her relative bearing had increased. We can alter course to portside 5 degrees to speed up the passing process. Let’s take close look again. This starboard side vessel ahead distance is less than 500 meters now. This bow distance is a sure sign for action. Why?