Le test comprend 80 questions aléatoires.
Total de questions sur ce sujet : 209
This vessel is sighted ahead and slightly to port. What is her situation? What will you do?
This is a vessel engaged in fishing vessel, with her nets fast on a obstruction. I will keep out of the way by rule 18 of the International Collision Regulations.
This vessel is aground. I will navigate with extreme caution given the nature of the hazard.
This is a vessel not under command at anchor.
This is a vessel aground. She appears to have been headed to starboard of my track and I will therefore alter course to port, passing under her stern.
The ship is sailing in shallow water with reduced Under Keel Clearance. If the ship is steaming with the engines at full RPM, what would be the speed in comparison to the speed achieved in deep water?
It would be very difficult to maintain full deep sea RPM on the engines and therefore difficult to assess the speed.
If a DSC distress alert is received on board your ship, what is the first action that should be taken?
Immediately answer the distress message on the correct radio frequency.
Contact SAR Authorities via nearest coast Radio station.
Listen for a distress message on the appropriate radio frequency for five minutes.
Determine how close your vessel is to the distressed vessel.
What are the three possible types of messages seen when there is an ECDIS alert?
Either an Alarm, an Indication or a Caution.
Either an Alarm, an Indication or a Caution.
Either an Alarm, a Warning or a Caution.
Either an Alarm, a Warning or an Information.
Two ships are meeting in a restricted channel as illustrated. Which of the following actions would be the most suitable to take on both vessels as they approach and pass each other?
Maintain speed and a straight course on the starboard side of the channel.
Keep as far as possible on the starboard side of the channel and maintain speed to retain effective steerage.
Increase speed slightly to pass each other as quickly as possible and thereby reduce the effects of “ship to ship” interaction.
Slow down if possible without losing steerage and be prepared for prompt application of rudder to counteract any swing as they approach and pass each other.
What is the two letter signal, to be used by flags, radiotelephony or radiotelegraphy, meaning “Calling All Ships”.
What is happening here?
These are two vessels engaged in fishing (pair trawling), showing the additional voluntary signals for shooting nets.
These are two vessels engaged in fishing (pair trawling), showing the additional volutary signals for hauling nets.
This is a vessel engaged in towing a disabled tow, restricted in its ability to manoeuvre, with a searchlight used to highlight the location of the tow.
These are two vessels engaged in fishing, using purse-seine gear. The searchlights are simply working lights.
You are in open water and clear conditions. You are approaching the pilot station when you hear this signal from a vessel ahead of you. What does it signify?
That the vessel is picking up his pilot.
That the vessel is altering his course to starboard.
That the vessel is starting his engine and resuming his passage.
That the vessel is operating astern propulsion.
You are approaching the port entrance. What do these lights mean?
Vessels may proceed – one-way traffic.
Vessels may proceed – two-way traffic.
A vessel may proceed only when she has received specific orders to do so.
A vessel may proceed only when she has received specific orders to do so, except that vessels which can safely navigate outside the main channel need not comply with this message.
What is the depth of an iceberg below the surface of the sea?
The draught of an iceberg is normally about 3/4 of its total depth.
The draught of an iceberg varies with the type of berg and its age.
The depth of an iceberg below the surface is always about one sixth of its total depth.
The draught of an iceberg is about the same as the visible part of the iceberg above the water.
What is the two letter signal, to be used by flags, radiotelephony or radiotelegraphy, meaning “Calling All Ships”?
The Master has decided to “single up” to a spring line at each end as the last lines to let go whilst unmooring. Which of the following methods should be used to hold the lines, whilst waiting for the order to “let go”?
The eye of the lines should be put on the bitts, fig. 2.
The line should be turned up on the bitts, fig. 1.
The line should be held on a stopper ready for immediate release, fig. 4.
The line should be kept on the warping drum of a deck winch, fig. 3.
When should a ship’s officer use some of the English language found in the IMO’s publication “Standard Marine Communication Phrases”?
When talking between ship and shore in a foreign land.
In circumstances described in all of the answers provided.
When talking on the VHF between ships of differing flag states.
When giving orders to a multi-national bridge team.
The tug has been released and is all clear. As officer in charge of that operation, should this be reported and to whom?
Reported all clear to the Bridge.
Report all clear to the tug.
No need for reporting as the order was given from the bridge.
Report all clear to the Engine Room.
The lights here show those that must be exhibited by a vessel engaged in towing, as per rule 24 of the International Collision Regulations. But how long is the tow behind this vessel?
It is less than 200 metres.
It is more than 50 metres but less than 200 metres.
Visual signals are used by aircraft in search and rescue operations to direct ships towards a casualty. The signals shown here are part of a sequence. What does it indicate?
The assistance of your vessel is no longer required.
The casualty is sighted and will require medical assistance.
The aircraft is short on fuel and is returning to base.
The aircraft is directing a vessel towards the casualty.
Why should a Ground Stabilised True Motion radar display not be used for anti-collision purposes?
Because this display is only ever used for navigation.
The true vector can never give an indication of collision risk with another ship.
The “aspect” of the target is confused, so the Regulations for Preventing Collisions cannot be accurately applied.
True motion does not provide the collision risk of targets as only true vectors are available.
The ship is required to be stopped in the water as quickly as possible, but without major changes to the ship’s heading. What is the most effective method to achieve this?
Put the engine full astern and keep the rudder amidships.
The use of the rudder hard over both sides combined with reducing engine power, a method known as “high frequency rudder cycling”.
Make a complete turn while reducing the engine power.
Make a zig zag manoeuvre while reducing the engine power.
What is the correct understanding of the term “bank effect”? If a ship was approaching the bank at an angle, what would be the effect on the ship?
The whole vessel would continue straight towards the bank and would require a large helm order to avoid going aground.
The vessel’s bow is pushed away from the bank.
The vessel’s stern is pushed away from the bank.
The vessel’s bow is attracted by the bank.
What type of vessel is this and from what direction are you seeing it?
This is a vessel engaged in fishing other than trawling, making way through the water, with outlying gear extending more than 150 m in the direction of the all-round red light. I am seeing her from astern.
This is a vessel engaged in pilotage operations, deploying or recovering a pilot. I am looking at her port side.
This is a vessel engaged in fishing other than trawling, making way through the water, with outlying gear extending more than 150 m in the direction of the all-round white light. I am looking at her port side.
This is a vessel engaged in pilotage duties at anchor. I am looking at her port side.
A tug is moving towards the bow of the ship to make fast and is in the vicinity of the ship’s shoulder, as illustrated. What specific danger should be considered when making this approach to the bow?
The positive pressure field at the ships bow may repel the tug and make the connection very difficult to establish.
The tug may be turned across the bow of the ship and also suffer a lose of stability with a danger of being turned over if touched by the ship.
The stern of the tug may be sucked in towards the bow and also suffer a reduction in the positive GM, making it very unstable.
All of the alternative answers.
What would be the stopping distance of a VLCC when proceeding at 8 knots in deep water and the engines are put “Full Astern”?
Varies, but can be determined from trial data.
The bridge Officer of the Watch (OOW) is plotting the ship’s position in the chartroom, when the ship is in collision with a fishing vessel. Why would the OOW be held responsible for the collision?
If the OOW is busy with the safe navigation of the ship he should have exhibited the “Not under Command” signals and made other ships keep clear.
If risk of Collision existed, the fishing boat should have contacted the larger ship over the VHF before the collision took place.
Under the Rules the fishing vessel should have kept clear of larger vessels and the OOW would not be responsible.
Under the Rules a proper lookout should be maintained at all times and by all available means.
You are proceeding along a narrow channel in front of another vessel, both heading for port. You hear this signal from the vessel behind you. What does it mean?
I intend to overtake you on your port side.
I am faster than you. Get out of the way.
I intend to overtake you on your starboard side.
I am operating astern propulsion.
The ship’s engine is going astern and the ship is piking up sternway. The rudder is amidships and the ship has a single, right-handed, fixed pitch propeller. What would be expected to happen?
The ship will probably start to change heading to starboard and stern speed will increase.
The ship will probably start to change heading to port and stern speed will increase.
The ship will move astern at an increasing speed and the stern start to swing off to starboard.
The ship will probably go straight astern without a change in heading and the stern speed will increase.
The ship is involved in a collision, what is the immediate action by the Officer of the Watch after the incident has taken place?
Contact the other ship and send the bridge lookout down to start taking soundings.
Stop engines and check over the side for any signs of pollution.
Call the Master and check the position for any immediate dangers.
Sound the General Alarm and stop engines.
You are approaching a port in a snowstorm. You hear this signal. What kind of vessel is it and what is it doing?
It comes from a vessel at anchor, less than 100 metres in length.
It comes from a vessel engaged in pilotage duties and it is making way through the water.
It comes from a vessel engaged in pilotage duties at anchor, over 100 metres in length.
It comes from a vessel restricted in her ability to manoeuvre.
The Master arrives on the bridge obviously under the influence of alcohol and states he is taking over the “con” of the ship. What actions should the Officer of the Watch (OOW) take in this situation?
Attempt to diplomatically avoid taking any actions that would put the ship or crew into danger and call the Chief Officer for assistance.
Tell the Master you do not think this is a good idea and retain control of the watch.
Tell the Master you consider him incapable of taking over the responsibility of the watch and that he should retire to his cabin and sleep it off.
Watch the actions made by the Master and if not dangerous, wait until the Master becomes more capable to take control or leaves the bridge.
If whistles are fitted on a vessel at a distance apart of more than 100 metres, will manoeuvring and warning signals, as defined by rule 34 of the International regulations for Preventing Collisions at Sea, be given on one or both whistles?
They shall be given on both whistles simultaneously.
Manoeuvring signals will be given only on the forward whistle; warning signals will be given on both whistles simultaneously.
They shall first be given on the forward whistle, followed by the after whistle, with a 5 second interval in between.
They shall be given on one whistle only.
A balanced rudder has some of the rudder area forward of the rudder axis. About how much area should this be to call it a balanced rudder?
What is the purpose of a sea anchor deployed from a lifeboat?
To hold the lifeboat in position with other survival craft.
To keep the lifeboat’s heading against the wind and sea and reduce drift.
To keep the lifeboat in a position close to the vessel.
To give a better signal to any aircraft searching for survivors.
What is the direction of wind associated with an anticyclone (area of high pressure) in the Northern Hemisphere?
Clockwise around the high pressure.
Anticlockwise around the high pressure.
Straight towards the centre of the anticyclone.
Directly away from the centre of the anticyclone towards the nearest low pressure.
How will the ship behave if it experiences a complete loss of power (blackout) in the situation illustrated?
The vessel will gradually swing to port and the speed will slowly reduce.
The vessel will gradually swing to starboard and the speed will slowly reduce.
The vessel will continue on course and the speed will slowly reduce.
The wind will push the vessel sideways, but the heading will not change.
You are proceeding along a coastal route when you hear this signal. The visibility is severely restricted. What does the signal mean?
There is a vessel at anchor in the vicinity. She is more than 100 metres in length. She is sounding an additional warning signal to approaching vessels, directing them to “keep clear”.
There is a vessel aground in the vicinity. She is less than 100 metres in length. She is sounding an additional warning to approaching vessels to “navigate with extreme caution”.
There is a vessel at anchor in the vicinity. She is less than 100 metres in length. She is sounding an additional warning to approaching vessels that they are “running into danger”.
There is a vessel aground in the vicinity. She is more than 100 metres in length. She is sounding an additional warning to approaching vessels that they are “running into danger”.
What does this flag mean?
I wish to communicate with you.
My vessel is stopped and making no way through the water.
I have a diver down; keep well clear at slow speed.
What, by definition in the International Collision Regulations, is a “vessel restricted in her ability to manoeuvre”?
A vessel which because of her draught in relation to the available depth of navigable water is restricted in her ability to deviate from her course and keep out of the way of another vessel.
A vessel engaged in underwater work, such as the laying, picking up or servicing of a pipeline, or which is in support of diving operations, performing dredging and mine-clearance or is deploying or recovering a pilot.
A vessel which from the nature of her work is restricted in her ability to manoeuvre as required by the Rules and is therefore unable to keep out of the way of another vessel.
A vessel which through some exceptional circumstance is unable to manoeuvre as required by the Rules and is therefore unable to keep out of the way of another vessel.
Which is the “CENTRE LINE”, in the figure?
The Fore and aft Centreline is indicated by D, in the figure.
The Fore and aft Centreline is indicated by B, in the figure.
The Fore and aft Centreline is indicated by C, in the figure.
The Fore and aft Centreline is indicated by A, in the figure.
You are on a power-driven vessel underway in open water. This vessel is sighted on the port bow on a steady bearing. What kind of vessel is it and what will your action be?
This is a sailing vessel not making way through the water. There is no risk of collision and I will maintain my course and speed.
This is a sailing vessel underway. I am the stand-on vessel and will maintain my course and speed under rule 17.
This is a vessel engaged in fishing. It is my responsibility to keep clear under rule 18 and I will alter course to starboard, sounding one short blast.
This is a sailing vessel underway, seen head-on. It is my responsibility to keep clear under rule 18 and I will take appropriate avoiding action.
What are the required data inputs into most gyro compasses to reduce any possible compass error?
All of the data in the suggested answers.
Maximum helm angle and rolling period.
What does this signal hoist mean?
I require medical assistance.
Do you require assistance?
I require immediate assistance.
What signal may be given by sound and by light to indicate that a vessel fails to understand the intentions or actions of another vessel, or is in doubt that sufficient action is being taken by the other to avoid collision?
Five prolonged blasts (flashes).
Five short and rapid blasts (flashes).
One prolonged blast (flash), followed by five or more short and rapid blasts (flashes).
Three short and rapid blasts (flashes).
When using the echo sounder in a river the soundings indicated may be incorrect, what would be the most probable cause of the error?
There should be no error with a properly working echo sounder.
The strength of the tide and current in the river.
The density of the water.
The IMO Standard Marine Communication Phrases are recommended to be used when the ship’s Officer is verbally talking to whom?
When talking between ship and shore personnel.
In circumstances described in all of the answers provided.
When giving orders on board with other seafarers.
When talking on the VHF between ships.
When a ship is lying at anchor in a tidal area using both forward anchors, to what particular aspect should the officer of the watch be paying special attention?
When the ship swings to the tide the direction of swing should be controlled to avoid the anchor cables becoming wrapped round each other.
The tension on both cables should be similar, to avoid one dragging and all the weight of the ship remaining on the other anchor only.
The ship will become controlled by the tide and the wind will not be allowed to have any effect on the direction the ship lies at anchor.
The two anchors will restrict the ships swing with the tide and the ship may not lie to the prevailing current and wind.
What are the immediate duties of the bridge Officer of the Watch when the ship suddenly runs into a fog bank?
Commence sounding the fog signal, engines on standby, call the Master and lookout, if not already on duty.
Commence sounding the fog signal and reduce speed to Slow Ahead.
Commence sounding the fog signal and call the Master and wait for him to arrive before taking any further actions.
Commence sounding the fog signal and if the radar indicates no echoes in the vicinity, proceed at the normal speed until ships are detected on the radar or until the fog lifts.
What corrections must be applied to the echo sounder reading to compare the depth of water with the depth printed on the chart?
The distance between the pulse Transmitter and Receiver.
Allowance for the ships speed.
When fastening synthetic fibre ropes such as polypropylene on bitts, for safety and better rope control it is recommended to:
Make it fast with round turns on the leading bitt alone, fig. 1.
Make it fast in a figure of eight fashion, fig. 3.
Make two round turns fast on the leading bitt and then figure of eight on both bitts, fig. 4.
Make it fast on the second bitt alone, fig. 2.
The ship is navigating in dense fog where the visibility is less than one mile. The Arpa radar is set on a range 12 miles on a course of 314° and own ship has a vector as shown. What is the vector mode selected on the Arpa?
Relative vectors, ground stabilised.
Relative vectors, sea stabilised.
What is the correct understanding of the term “a ship with good Directional Stability”?
A ship which when the rudder is left amidships, it will continue on approximately a straight course.
A ship which when a rudder angle is applied and the ship starts to swing, will continue to swing even after the rudder is returned to amidships.
A ship which will maintain its course unless large rudder angles are applied.
A ship where the amount of positive transverse stability (GM) will vary with the direction of the ship’s head.
A man is reported to have fallen overboard and the Officer of the Watch releases the lifebuoy and starts a man overboard manoeuvre, who are the first persons onboard he should inform?
The crew quarters for extra lookouts.
Chief Officer and lifeboat party.
What action should the Officer of the Watch (OOW) take if he is forced to make a major deviation from the voyage plan?
There is no special action necessary.
Check that the deviation will not lead into danger.
Make an appropriate entry in the Log Book.
What can be used to reduce the effect of the state of sea-water?
Which of the four calculations illustrated is the correct one to determine the latitude of the observer when the sun is on the meridian?
Calculation 3 is correct.
Calculation 2 is correct.
Calculation 1 is correct.
Calculation 4 is correct.
Where can a ship expect an act of piracy to take place?
At the south end of the Red Sea.
What is the weather associated with being in the centre of an Anticyclone (a region of High Pressure)?
Strong winds and heavy rain.
Light winds and fair weather, sometimes fog.
Persistent rain and very humid weather.
Strong winds but with very little rain.
According to the International Regulations for Preventing Collisions and the illustrated lights, what type of vessel is this and from what direction is it viewed?
This is a vessel engaged in fishing other than trawling, making way through the water, with outlying gear extending more than 150 m in the direction of the all-round white light. Looking at its port side.
This is a vessel engaged in pilotage duties at anchor. Looking at its port side.
This is a vessel engaged in fishing other than trawling, making way through the water, with outlying gear extending more than 150 metres in the direction of the all-round red light. Looking at it from astern.
What is the purpose of a sea anchor?
To keep the lifeboat in a position close to the vessel.
To adjust the drifting speed of the lifeboat.
To give a better signals to any aircraft searching for survivors.
To keep the lifeboat steady against the sea/wind.
You are on a tug and are towing an unmanned barge. You are restricted in your ability to manoeuvre. The total length of the tow is 219 metres. What daylight signals are required by the International Regulations for Preventing Collisions at Sea?
A diamond shape, where it can best be seen shall be displayed on the tug and the tow. Three shapes shall also be displayed in a vertical line, the upper and lower being balls and the middle one a diamond. Diamond shape.
A diamond shape, where it can best be seen, on the tug only. Three shapes shall also be displayed, being three balls in a vertical line.
Three shapes shall be displayed forward on the tug, in a vertical line, the upper and lower being balls and the middle one a diamond.
Three shapes shall be displayed on the tug, where they can best be seen, in a vertical line, the upper and lower being balls and the middle one a cylinder. The signal flag “T” shall also be flown on the tug. A diamond shall be displayed aft on the tow.
Which statement best describes how land moves, if at all, on an ECDIS set in North-up, relative motion mode?
This is a feature only seen on radar displays.
The land is always in the middle of the screen.
Land on the chart screen moves relative to the ship symbol.
Land is stopped with the vessel symbol moving across the sea floor.
How can a new officer, just boarding a ship, ensure that he knows the location and operation of all navigational and safety equipment and take account of the operating limitations of such equipment?
By following the standard company Induction procedures for a bridge watchkeeping officer.
By using the equipment on regular watchkeeping duties.
The certificate of competency will ensure the officer has suitable competence in operating the bridge equipment.
By asking other officers and practicing with the use of the equipment.
How can the effects of Squat be minimized, when a ship is proceeding in shallow water?
Maintain a speed of about 6 knots and use minimal rudder when manoeuvring.
Enter the shallow water with a stern trim and proceed at a moderate speed.
Decrease the speed and keep this ship to the centre of the channel where the water is probably deepest.
Maintain a slow speed just sufficient to maintain steerage.
In a canal without water flow, if a vessel was approaching a bank at an angle, what would be the probable effect on it?
The vessel’s stern is pushed away from the bank.
The vessel’s bow is attracted by the bank.
The vessel’s bow is pushed away from the bank.
The whole vessel would continue straight towards the bank and would require a large helm order to avoid going aground.
When splicing an eye on a mooring wire (using the recommended 5 full tucks and 2 half tucks) the effective breaking strength of the wire may be affected by the splice. What would be the anticipated change in the breaking strength of the wire?
A reduction in strength of 1 % to 5 %.
A reduction in strength of 10 % to 15 %.
A reduction in strength of 30 % to 40 %.
No reduction in strength.
Where can the size of the Magnetic Compass Error be found?
By taking the error from the Deviation Table on the bridge.
By taking a transit bearing of two fixed geographical positions and comparing it with the bearing of the same points on the chart.
On the chart in the centre of the compass rose or by reference to the Variation chart, taking into account the annual changes.
By reference to the last entry in the Compass Error Log Book.
In the diagram, the amount of water under the keel is indicated by the letter “C”. Which bridge instrument would measure this value?
What is understood by the term “Dew point” of the air?
The temperature of the water vapour in a cloud.
The temperature at which condensation in the air forms into water droplets.
All of the suggested answers.
The “Dew point” is the point at the centre of an Anticyclone.
The ship has a single fixed pitch right-handed propeller and is going astern as illustrated. What is the most likely way the ship will react in these circumstances?
The stern will “back” into the wind and the ship’s heading will swing to starboard.
The stern will fall off to starboard, making the heading swing to port.
The bow will “seek” the wind and the ship will swing to port.
The ship will go straight astern and the heading will remain approximately the same.
Why should Ground Stabilised True Motion display mode be avoided when using the ARPA for anti-collision purposes?
The collision regulations are based on ship courses through the water.
The true vector can never give an indication of collision risk with another ship.
True motion does not provide the collision risk of other ships.
The Relative Motion display and relative vectors is the only display to use for anti-collision purposes.
The Second Officer, when on watch on the bridge, is often referred to as the OOW. What does OOW actually stand for?
On official watchkeeping.
Which of the following answers correctly specify the following most common rudders? a) UNBALANCED, b) BALANCED, c) SEMI-BALANCED and d) UNDERHUNG BALANCED. i. e. The number in the picture is related to the letter adjacent to the name of the rudder.
1 = d, 2 = a, 3 = b and 4 = c.
1 = b, 2 = c, 3 = d and 4 = a.
1 = a, 2 = b, 3 = c and 4 = d.
1 = c, 2 = d, 3 = a and 4 = b.
Which option best completes the following statement? An operator using ECDIS, will notice an out of position navigation buoy because:
There will be a flashing alarm on ECDIS showing which one is out.
A local port authority would send an automatic signal to ECDIS.
The radar return and ENC buoy symbol will not coincide.
It is coloured orange on an ECDIS display.
What corrections must be applied to the echo sounder reading to compare the depth of water with the depth printed on the chart?
Allowance for the ships speed.
The distance between the pulse Transmitter and Receiver.
Is the location of a vessel’s standard compass binnacle critical?
Yes, it should be on the fore and aft centreline of the ship.
Yes, for the reasons stated in all of the suggested answers.
Yes, it should be sited on a non-metallic base if possible.
Yes, it should be away from major electrical power cables.
During an STS operation with one ship at anchor, should an anchor watch be maintained?
Anchor watch responsibility rests with the discharging vessel which would be the vessel which is anchored.
Both ships have normal anchor watch responsibility in addition to watching ship to ship fendering, mooring etc.
Anchor watches are not kept as the duty officers will be on deck conducting the cargo operations.
Anchor watch responsibility rests with the vessel which has its anchor down and the ship to ship connections is the responsibility of the other vessel.
The positions of the ship provided by the GPS receiver should always be verified by other means. Which of the following suggested methods would be the most accurate?
Bearing and distance from a navigational buoy.
Radar bearings of three distinctive shore objects.
Radar ranges of three distinctive shore objects.
A DR updated position from the last reliable one.
When should gangway nets be rigged?
When it is deemed necessary by the Master of the Chief Officer.
Whenever the gangway is rigged.
Between sunset and sunrise.
Whenever the gangway is regarded as unsafe.
You are in an area of restricted visibility, close to a port. You hear this signal. What vessel does it come from and what additional information does the signal provide?
A vessel at anchor, less than 100 metres in length. She is sounding the additional signal top give warning of her position.
A vessel at anchor, more than 100 metres in length. The additional signal indicates that her cable extends at least 25 metres from her bow.
A vessel at anchor, more than 100 metres in length. She is sounding the additional signal to give warning of her position.
A vessel aground, more than 100 metres in length. The additional signal indicates which side the clear water lies on.
Who is ultimately responsible for the voyage plan?
The Officer of the Watch (OOW) on duty.
The Second Officer as the official Navigation officer.
The ship owner will provide overall parameters within which the ship must follow.
What is “AIR DRAUGHT”, in the figure?
Air draught is indicated by C, in the figure.
Air draught is indicated by B, in the figure.
Air draught is indicated by D, in the figure.
Air draught is indicated by A, in the figure.
When the temperature of the air increases with height it is known as a “Temperature Inversion” and may influence the performance of some instruments on the ship. What should the bridge Officer of the Watch be prepared to happen?
The radar will be show abnormal sea clutter as the pulse is trapped by the inversion.
The GPS may give errors of position because of interference of incoming signals from the satellites.
Abnormal ranges of VHF RT and Second Trace Returns on the radar.
The bearings obtained from the Directional Finder (DF) will not be as accurate as normal.