Capt. Poswal Pet Questions for 2MFG Orals

Table of Contents

MOB. Starboard Side. What will be your first three actions?

  • Change to Manual Steering. Give hard over to STBD Side
  • Release MOB Marker from Bridge Wing.
  • Mark MOB in GPS and ECDIS.
  • Call Master and post an extra lookout
  • Sound alarm for Man Over Board (—) and hoise flag OSCAR
  • Execute Williamson’s Turn or Anderson Turn
  • Transmit Distress message on VHF/ MF
  • PRepare Rescue Boat and get ready to rescue the casualty.

What information you get from Routeing Charts?

  • Essential in passage planning for Ocean Voyages
  • give routes and distances between major port around the world
  • Each part has 12 versions, one for each month of the year.
  • Published in each month for 12 regions
  • They give information about:
  • Wind Rose;
  • Currents;
  • Dew point temperature;
  • Load Line zones;
  • Seawater Temperature;
  • Ice Limits;
  • Isobars;
  • Routes and distances between major ports around the world
  • 12 regions for which Routeing Charts are published are:
    • North Atlantic Ocean;
    • South Atlantic Ocean;
    • North Pacific Ocean;
    • South Pacific Ocean;
    • Indian Ocean;
    • The Mediterranean and the Black Sea;
    • Gulf of Mexico and Carribeans;
    • Malacca Strait and Marshal Islands;
    • The Red Sea and the Arabian Sea;
    • The Bay of Bengal;
    • The East China Sea;
    • South China Sea

Enlist all the effects of Shallow Water

  • When the depth of water is less comparing to the draft of the ship. The effect becomes evident when the depth of water is less than 1.5 times of the draft of the ship. Following effects are evident:
    • Sluggish Movement;
    • Erratic Steering, slow response;
    • Vibrations;
    • Smelling the ground;
    • Squat;
    • Bow cushion and bank suction effect;
    • Canal Effect;
    • Increase in Bow Waves

What is smelling the Ground?

  • It occurs when a ship is rearing on extremely shallow depth of water, such as Shoal;
  • Ship is likely to take a sudden shear;
  • Ship first goes towards the shallow, then violently moves away from it;
  • Movements of sluggish ship may suddenly become astonishingly lively;
  • These effects are called as smelling the ground.

Which rule says don’t reduce speed at open sea, or not use telegraph?

Rule 8 (c). “If there is a sufficient sea room, alteration of course alone may be the most effective action to avoid a close quarter situation provided that it is made in good time, is substantial and does not result in another close-quarters situation.”

Which SOLAS Regulation, Bridge Equipment comes under?

  • SOLAS Chp V
    • Regulation 19 – Carriage requirements for Shipborne Navigational Systems and Equipment
    • Regulation 20 – Voyage Data Recorders
  • All equipment comes under this Regulation except Course Recorder, Chronometer, and Sextant.

Is Rule 13 Overtaking applicable in RV?

No. Rule 13 is only applicable, when in sight of one another.

What is Fog Signal for vessel at Anchor?

  • A vessel of less than 100 meters in length shall at an interval of not more than 1 minute ring a bell rapidly for 5 seconds
  • A vessel of 100 m or more in length shall sound in forward part of vessel, rapid ringing of Bell for 5 secs, followed immediately from aft part, souding of Gong for 5 secs at 1 minute interval.
  • A vessel in giving warning of her position and possible Collision may sound Morse Code “R” (.-.)

On a chart, a light is shown as 20 m, what does this indicate?

It means, 20 M is the Nominal Range, at which the light can be seen in conditions where visibility is 10 nm.

What is Oculting and Isophase?

  • Occulting: A light in which the total duration of light in the period is clearly longer than the total duration of darkness.
  • Isophase: The light and darkness have equal duration.

Specifications of Anchor Ball:

  • Ball: Diameter of not less than 0.6 m. Black in color.
  • Cone: Base diameter not less than 0.6 m and Height = Diameter
  • Cylinder: Diameter- 0.6 m, Height- Two times the diameter
  • Vertical separation shapes shall be at least 1.5 meters

Which Rules applicable in all vicinity and in sight of one another.

Section B, Part 2 Rules 11- 18

You received a Distress alert from 150 nm, as an OOW? Take action.

  • Log alert and inform Master
  • Set watch on respective Radiotelephony for voice communication.

What is transverse thrust?

  • It is sideways thrust which occurs while the ship’s propeller is rotating. The thrust of the propeller blade is having two components
    • Fore and aft,
    • Very small athwartship
  • The athwartship direction thrust is called transverse thrust.
    • For Right Handed Propellers:
      When the ship is going ahead, the pressure on the lower/ deeper blade is more than the upper ones, so the bow will turn to port and stern will go to starboard.
Capt. Poswal Pet Questions for 2MFG Orals 1
For Right Handed Propeller
  • Opposite is for Left Hand Propeller

When to take Long by Chron and why?

Long by Chron of Sun is taken when altitude is more than 20 degrees, so as to eliminate the higher error of Refraction.

What is Parallel Indexing? Can we use it when Gyro fails?

  • A bearing line is drawn parallel to the original course with a known and fixed perpendicular distance.
  • The technique is used to monito the progress of the vessel and to minimize errors
  • It is used to keep vessel at a safe distance from shore line and land.
  • Paraller Indices are set of perpendicular lines that are made to appear on PPI, when desired to facilitate safe navigation of ship in coastal waters
  • Parallel Index can be used when Gyro fails. When Gyro fails the Radar will go in Heads up mode and PI can be used.

Where are Special Marks used?

These are not primarily intended to assist in Navigation but indicate a Special Area or feature referred in appropriate Nautical documents.
i. Ocean Data Acquisition System (ODAS) Buoy;
ii. Traffic Separation Schemes (TSS);
iii. Military Exercise zone marks;
iv. Protected Areas;
v. Historic Wrecks;
vi. Oil Wells;
vii. Firing Areas;
viii. Spoil Ground.

How you will check that charts are corrected?

By checking CNTMs and then check whether corrections have been done or not on chart and also check for edition.

How you will know your Anchor is dragging?

  • Check the ship’s position at frequent intervals to confirm if the vessel is outside the swinging circle. If it is outside, the vessel is likely to be dragging anchor.
  • Check Anchor chain for slipping, a small pole with a cloth as flag like arrangement can be tied to links to to understand the slipping of anchor chain.
  • Extra weight and vibration or anchor cable
  • When the ship is dragging anchor, she will have a negative speed over the ground on GPS.
  • If the vessel is dragging anchor, anchor chain will go to long stay, then rapidly come to an up and down and again long stay.

Duties of OOW at Anchor?

  • Determine and plot ship’s position on the chart as soon as possible;
  • Check regularly, if ship is at anchor by taking bearings of fixed Navigational Marks;
  • Ensure that a proper lookout is maintained;
  • Observe meteorological and tidal conditions and the state of the sea;
  • Notify the Master, if ship drags Anchor;
  • Ensure that the state of readiness of main engines and the machinery is in accordance with Master’s instructions;
  • If visibility reduces notify the Master;
  • Ensure that the ship exhibits appropriate lights and shapes and appropriate sound signals;

How to calculate Swinging Circle?

Distance from Bridge wing to Forecastle is 150 meters, if the ship is anchored with 5 shackles on deck, then
Swinging Circle = 150 + (27.5 x 5)/ 1852
= 287.5/ 1852
= 0.155 nm
1 nm = 10 cable

What is Squat? How to find it? what are the factors affecting it?

  • The Squat is an increase in the draft when the vessel is traveling through the water with a limited Under Keel Clearance.
  • It happens when UKC is less than the draft.
  • The Squat is the bodily sinkage of a ship in the water when making headway.
  • Following factors affect Squat:
  • High Speed (Squat Directly proportional to Speed²)
  • High Propeller Speed
  • Shallow depth of water
  • High Block Co-efficient (Cb): Block coefficient is the ratio of the immersed volume of Ship relating to the cross-section of water within the canal or river.

Blockage Factor is the Proportion of Midship section of ship divided by Cross-sectional area of the Channel, River


Static UKC: Lesser UKC, the more is Squat.
Squat increase if the ship is close to the Bank of River or canal
When a ship is passing or overtaking another vessel in a river or canal. the squat can increase up to twice the normal value.

Maximum Squat in Open Waters = Cb x V²/ 100

Maximum Squat in Confined Waters = Cb x V²/ 50

Precautions to take before Heavy Weather?

  • Verify vessel’s position and consider re-routing;
  • Update weather report and plot storm movement;
  • Avoid slack tanks and avoid FSE in stability;
  • Inform all departments about the heavy weather;
  • Rig lifelines forward and aft;
  • Close all deck ventilation;
  • Anchors to be well secured, spurling pipe cemented, break light, bow stopper well secured and additional lashing at hawse pipe.
  • All derricks and cranes to be well secured.
  • Make sure accommodation ladder is well secured.
  • Make sure all movable objects are secured.
  • Secure Bridge against heavy rolling and pitching;
  • Obtain and update weather reports continuously and update position;
  • Make relevant log entries;

What all rules comes under RV?

In RV, except Rules 11 to 18, i.e Part B, Section 2 and Rule 34, all rules 1-10, 19, 35 comes under RV

You are PDV, there is anchored vessel, how will you pass?

Pass stern of Anchored vessel. As by going from bow, we might get in contact with Anchor Cables

What is Bank Cushion Effect?

Bank Cushion Effect:
When a ship moves closer to the bank, the hydrodynamic is distributed.
Ship’s bow will experience a sheer away from the bank. This is called Bank Cushion Effect
The forward portion of the ship maintains positive pressure.

Explain Theoretical Sunrise and Sunset?

Theoretical sunrise and sunset occurs when true sun’s centre is on the observer’s Rational Horizon
True Altitude of Sun is 0 degree and its True Zenith distance 90 degree.
Time of theoretical sunrise and sunset can be obtained by solving PZX triangle, in which ZX is 90 degrees.

How will you determine error by observing Jetty?

The difference between the observed direction of jetty and charted direction when to ship is fully alongside will give compass error.
This will only be accurate if the vessel is close to the jetty throughout its length and the jetty extends to the full length of vessel. This may not be accurate if either the bow or stern is away from the jetty or the jetty os not complete.

What are leading lights?

Leading Lights are a pair of light beacons used to indicate a safe passage for vessels entering a channel.
These beacons consist of two lights that are separated in distance and elevation, so that when they are alligned with one above the another, they provide a bearing.
These bearing lines are used to indicate track to be followed when approaching a port or a channel.
The diffrence between the charted bearing and the heading of the ship when on the leads can be used to determine the error on both Gyro and Magnetic Compass.

Day Signal of CBD?

One Cylinder.

Day Signal of Aground vessel and vessel dragged anchor.
Vessel Aground: Three Black Balls in a vertical line.
Anchor Dragging: Daytime Signal: Flag Yankee, NUC Vessel Lights i.e. Stern Lights, Side Lightsm Two all-round Red Lights

Course Recorder Carriage Requirement. What enteries are to be made on Course Recorder and as per which Regulation in SOLAS.
Chp 5, Reg 28 of SOLAS: Records of Navigational Activities and daily Reporting.
Normally following enteries are made:
Ship’s position;
Ship’s course speed;
Details of external and internal conditions that are affecting the ship’s voyage or the normal safe operation of the ship.

Is it mandatory to follow VTMS?
Yes it is mandatory in territorial waters, as per SOLAS Chp 5, Reg 12.

Path of TRS in NH and SH?
In NH, TRS travel between W and WNW.
In SH, it travels between W and WSW.

Which wind blows in TRS?
In TRS, wind of gale forces (34 kts or force 8) or more blows spirally inwards Anti-clockwise in NH and clockwise in SH.

Which quadrant is most dangerous in TRS in NH?
In NH, dagerous quadrant is RHSC and LHSC in SH.

How much pressure during Cyclone?
Pressure drops of 20 mb is sufficeint to cause a TRS i.e. 990 mb

How will you know that you are grounded? What will be your first action in case of grounding?
Speed will be Zero. Start with, Mark in VDR and mark entry in Course Recorder and Official Log Book.

What is your duty relating to VDR during any accident?
Press the black button on VDR

Define Rational Horizon.
It is agreat circle on celestial sphere. Every point on which is 90 degree from Observer’s Zenith

What information we get from Wheel House Poster?

Ship’s Particular- Name, Call Sign, GRT, MRT, Maximum Displacement, Deadweight;
Steering Particulars;
Propulsion Particulars;
Anchor Chain details;
Thruster effect;
Turning circles at maximum rudder angle;
Stopping Characteristics;
Emergency maneuver;
Man overboard rescue maneuver

Download Wheelhouse Poster here

Steering failure in Narrow Channel or Coastal Waters. Action?

  • Inform Master and Engine Room.
  • Stopping Engine
  • Alert other ships nearby by NUC Lights/ Day Shapes, Whistle or VHF.
  • Transmit safety message on VHF so that vessel in vicinity keep clear.
  • Confirm vessel position.
  • Estimate drifting direction and speed.
  • Follow Steering Failure Contingency Plan
  • PRepare for anchoring if in shallow waters.
  • Inform VTS.
  • Change AIS Status.
  • Prepare for Emergency Steering.

What is Mean Sun and True Sun?

True Sun’s apparent path is Ecliptic.
Mean Sun apparent path is Equinoctial

Which Rules talk about use of RADAR while talking action?
Rule 8 (b)- “Any alteration of course/ speed to avoid collision shall if the circumstances of the case admit, be large enough to be readiy apparent to another vessel observing visually or by RADAR, a succesion of small alteration of course and speed shoud be avoided.”

In RV, aground vessel signal for a very small vessel?
As per Rule 35 (i) and j:
i. A vessel of 12 m or more but less than 20 m in length shall not be obliged to give bell signals prescribed in Para (g) and (h) of Rule 35.
However, if she does not, she shall make some other efficient sound signals at interval of not more than 2 mins.

What are ECDIS Safety Settings?

  1. Shallow Contour: Value selected by mariner normally less than safety depth.
  2. Safety Contour: Ship’s Draft + UKC + Squat + ZOC Correction – Height of Tide
  3. Safety Depth: Ship’s Draft + UKC to be used by ECDIS to emphasize sounding on the display equal to or lesser than this value
  4. Deep Contour Setting

What are some examples of Good Seamanship?

When underway keep clear of vessel at anchor
Do not anchor close to another vessel at anchor
In thick fog having zero visibility and without RADAR, stop or anchor the vessel.
When rounding a bend in a channel, the vessel running against the tide should keep clear of a vessel running with the tide.
Do not cross ahead cross ahead of a vessel at Anchor to prevent drifting on to her, due to tide.
While taking action to avoid collision do not cross ahead of other vessel underway.
In a narrow channel make allowance for shallow water affects and interaction.

Make a Passage Plan Table. as per Poswal.
Sr. No. WP No. Position Sounding Speed ETA to WP UKC Sounding DTG PFI PFM BWL E/R Station
Lat Long Manned/ UMS

Navtex Stations Special Area Nav Area ECDIS Settings Remarks

When to call Master?

  • If RV is encountered or expected.
  • If difficulties are experienced in maintaining the course.
  • If movement of other ships or traffic causing concern
  • When any distress signal or warning is received.
  • If unexpectedly, land or navigational mark is sighted or change in sounding occurs
  • On breakdown of Engines, Steering Gear or any other essential Navigational Equipment.
  • If any Radio Equipment malfunction
  • In heavy weather, if in doubt about the possibility of weather damage.
  • If vessel’s security concerns arises.
  • In any other emergency or in any doubt.
  • If ship meets any hazard to navigation such as Ice or Derelict.
  • For more details check here

Visibility of Daylight Signalling Lamp?

Daylight Signalling Lamp required as per SOLAS Chp 5, Reg
“a daylight signalling lamp, or other means to communicate by light during day and night using an energy source of electrical power not solely dependent upon the ship’s power supply.”
Its purpose is to communicate by light during day and night
Signalling Range by day: 2.4 nm (4.5 kms) and by night, 19.4 nm (36 kms)

Aground vessel sound signal?
Three distinct strokes on the bell, befor and after rapid ringing of bell.

What is Spring and Neap Tide?
Spring Tide: Spring Tide occur when the Moon is either new or full. The Sun, the Moon and the Earth are aligned. When this happens, their collective gravitational pull on the Earth’s water is strengthened.
In Spring Tide, difference between hight and low tide is greatest
Neap Tide: During Neap Tidem the diffrence between high and low tide is the least. Neap Tide occur twice a month, when the Sun and Moon are at right angles to the Earth. When this is the case, their total gravitational pull in Earth’s water is weakened because it comes from two diffrent directions.