Colregs Scenarios Flashcards
General Technique
Describe
Define
Decide
Defend
PDV v CBD
Rule 18 - PDV to avoid impeding
CBD on port side crossing
Rule 15: they should give way
but
18d: I am to avoid impeding
so
Action: sound 1 short and alter to stbd to parallel, then consider slowing down to expedite resolution of situation
Vessel approaching from 22.5° abaft beam
THIS IS NOT OVERTAKING
RULE 18 THEREFORE WINS
KEEP CLEAR IF NOT PDV
RAM crossing Port Side
Rule 15 does NOT apply here.
R18; I am to keep out of her way.
While there is nothing to prevent me from altering to port within the rules, in the interest of good seamanship I would
Sound 1 short blast + supplement with signal lamp
Bold and substantial alteration to stbd
Pass ahead at a safe distance
Continue to monitor until past and clear
Fishing Vessel crossing from Port Side in TSS (in lane)
FV Is not to impede my passage therefore continue to monitor with caution
Sound 5 short and rapid, supplement with lamp
If searoom allows, a/c to stbd to cross ahead
Sailing Vessel on port side in Traffic Separation Zone, encroaching hdg 90* to own
Series of Compass Brgs, ascertain RoC.
As S/V not in lane, R18 wins, therefore, searoom allowing sound+flash 1, a/c to stbd to pass ahead, staying in lane
R19
Actions?
No action required, no risk of collision exists
(OA Line not intersecting with centre)
Lookout reports hearing fog signal dead ahead.
Actions?
Fog signal unlikely to be tracked vessel due to range.
Take all way off, and navigate with extreme caution
You can hear a fog signal yourself now.
It has no pattern (i.e. continuously sounding)
Continuous sounding with fog signalling apparatus is a distress signal as per ColRegs.
GA
Master
Prepare to render assistance
What could this be?
Actions?
A vessel under 50m in length at anchor (Rule 30 b)
A sternlight (Rule 22)
A sailing vessel under 7m in length (Rule 25 d i)
A vessel under oars (Rule 25 d ii)
A power driven vessel under 7m in length, capable of doing less than 7 knots (Rule 23 d ii)
A power driven vessel under way, at such a distance that her sidelights are not visible (Rule 22)
A vessel less than 12m in length aground (Rule 30 f)
Could also be:
Survival Craft
Shore light
Take a series of compass bearings, ascertain if risk of collision exists. Utilise all available means to establish nature of vessel. Conduct navigational assessment.
Navigate with caution and if in any doubt, keep well clear.
What is this ship? Actions?
Power driven vessel operating in NON DISPLACEMENT MODE, probably over 50m in length. Underway, possibly making way, seen from starboard aspect.
Take a series of compass bearings to ascertain risk of collision. R15 scenario, I am on her own starboard side. Expectation is that she alters her course to starboard to pass astern of me. However, as she is operating in non-displacement mode and not subject to drag, she is likely proceeding at a high speed and may continue to pass ahead of me.
What is this vessel?
Actions?
Vessel engaged in fishing. Underway, making way. Length unknown, seen from right ahead.
Take a series of compass bearings to ascertain if risk of collision exists. If bearing is steady and range decreasing, I would take this to mean that ROC does exist.
This is a rule 18 scenario. I am obliged to keep out of her way. I would sound one short blast supplemented by the manoeuvring lamp, make a bold and substantial alteration of course to starboard to pass her at a safe distance, continuing to monitor until past and clear.
There is nothing to stop me going to port, but I would prefer to keep my starboard side clear in the interest of good seamanship.
This is a fishing vessel, underway and making way. Length unknown, seen from port aspect. Outlying gear extending more than 150m from her stern.
Take a series of compass bearings to ascertain if risk of collision exists. If bearing is steady and range decreasing, I would take this to mean that ROC does exist.
In that case, I would sound two short blasts on the whistle, supplemented by the manoeuvring lamp, making a bold and substantial alteration of course to port to pass ahead of her at a safe distance, continuing to monitor until past and clear.
Altering to starboard is unlikely to resolve the situation as I don’t know how long the outlying gear truly is. Similarly, slowing down would not resolve the situation and I may end up running over the gear anyway.
What is this vessel?
Actions?
Fishing vessel, underway and making way.
Seen from starboard side, length unknown.
Engaged in purse seine fishing.
Take a series of compass bearings to ascertain if risk of collision exists. If bearing is steady and range decreasing, I would take this to mean that ROC does exist.
This is a rule 18 scenario and so I would sound one short blast on the whistle, supplemented with the manoeuvring lamp, making a bold and substantial alteration of course to starboard to pass ahead of the fishing vessel at a safe distance, continuing to monitor until past and clear.
You see this astern of you.
What is this vessel?
Actions?
Vessel Not Under Command. Length unknown. Underway, making way.
Take a series of compass bearings to ascertain if risk of collision exists. If bearing is steady and range decreasing, I would take this to mean that ROC does exist.
An interesting case. Rule 13 states that ANY vessel, whilst overtaking, shall keep clear of the vessel being overtaken. However, under Rule 3, it explicitly states that a NUC vessel cannot manoeuvre as required by the rules. Therefore, I would sound one short blast on the ship’s whistle, supplemented by the same on the manoeuvring lamp, making a bold and substantial alteration of course to starboard, allowing the NUC vessel to pass clear down my port side at a safe distance, continuing to monitor until past and clear.
What is this vessel?
Actions?
(Could it be anything else?)
Wing in Ground Craft taking off, landing or in flight near the surface. Seen from right ahead.
Take a series of compass bearings to ascertain if risk of collision exists. If bearing is steady and range decreasing, I would take this to mean that ROC does exist.
WIG craft shall not impede the passage of all other vessels as per R18. However, they are expected to comply as a PDV with the Rules of Part B.
Being cognizant of the fact that the WIG craft would be operating at a very high speed (80-100knots), and that delaying my action would not aid the situation, I would sound one short blast on the whistle, supplemented by the same on the lamp.
Make a bold and substantial alteration of course to starboard and expect them to do the same.
What is this vessel?
Actions?
Not Under Command. Length unknown.
Underway, making way.
Take a series of compass bearings to ascertain if risk of collision exists. If bearing is steady and range decreasing, I would take this to mean that ROC does exist.
By definition, a NUC vessel cannot manoeuvre as required by the Rules or keep out of the way of another vessel.
Therefore, I would either sound and flash two to pass astern at a safe distance, or make a significant and early reduction in speed to allow them to pass well clear ahead, continuing to monitor until past and clear.
What is this vessel? Fog signal?
Actions?
Vessel aground. Length unknown.
Fog Signal:
3 strokes, 5s bell, 3 strokes (+5s gong if LOA > 100m). May also sound Uniform ( . . - ) or Lima ( . - . . )
Take all way off.
Verify own vessel position.
Call Master.
Prepare to render assistance.
What is this vessel?
Actions?
Vessel constrained by draught (CBD), underway possibly making way.
Seen from starboard aspect, probably more than 50m LOA.
Take a series of compass bearings to ascertain if risk of collision exists. If bearing is steady and range decreasing, I would take this to mean that ROC does exist.
Sound and Flash 1, bold and substantial alteration to starboard to pass ahead at safe distance, continue to monitor until past and clear.
CANNOT go to port, still R15 base scenario but I am not to impede so will take action accordingly.
What is this?
Actions?
Power driven vessel engaged in towing
Length of tow less than 200m
Towing vessel probably over 50m
Under way possibly making way
Seen from starboard aspect
Take a series of compass bearings to ascertain risk of collision. If range decreasing and bearing steady, risk of collision deemed to exist.
This is a rule 15 scenario as she is not restricted, so I would maintain my course and speed and continue to monitor.
If she fails to take any action, I would sound 5 short and rapid blasts on the ship’s whistle, supplemented by the manoeuvring lamp to signal my doubt as to her intentions, and call the master (if applicable)
If she STILL fails to take action, under rule 17)a)2), I would take action to avoid collision.
In this instance, I would sound one short blast, supplemented by the manoeuvring lamp, and make a bold and substantial alteration of course to starboard, ideally passing ahead at a safe distance but paralleling the other vessel if necessary.
What is this?
Actions?
Power driven vessel engaged in towing a partially submerged or inconspicuous object (not a dracone) less than 25m in breadth and less than 100m in length
Length of tow less than 200m
Towing vessel less than 50m
Underway possibly making way
Seen from starboard aspect
Take a series of compass bearings to ascertain risk of collision. If range decreasing and bearing steady, risk of collision deemed to exist.
This is a rule 15 scenario as she is not restricted, so I would maintain my course and speed and continue to monitor.
If she fails to take any action, I would sound 5 short and rapid blasts on the ship’s whistle, supplemented by the manoeuvring lamp to signal my doubt as to her intentions, and call the master (if applicable)
If she STILL fails to take action, under rule 17)a)2), I would take action to avoid collision.
Sound and flash 1, bold a/c to stbd to pass ahead at a safe distance, paralleling their course if necessary.
What is this?
Actions?
Power driven vessel engaged in towing
Tow length over 200m
Towing vessel less than 50m
Underway, possibly making way
Seen from starboard aspect
Take a series of compass bearings to ascertain risk of collision. If range decreasing and bearing steady, risk of collision deemed to exist. However, I would be Cognizant that risk of collision may still exist with an appreciable change in bearing, given the length of tow
This is a rule 15 scenario as she is not restricted, so I would maintain my course and speed and continue to monitor.
If she fails to take any action, I would sound 5 short and rapid blasts on the ship’s whistle, supplemented by the manoeuvring lamp to signal my doubt as to her intentions, and call the master (if applicable)
If she STILL fails to take action, under rule 17)a)2), I would take action to avoid collision.
Sound and flash 1, bold a/c to stbd to pass ahead at a safe distance, paralleling if necessary.
What is this?
Actions?
RAM vessel engaged in underwater operations
Underway, making way
Vessel length less than 50m
Seen from port aspect
Take a series of compass bearings to ascertain risk of collision. If range is decreasing and bearing steady, risk of collision deemed to exist.
Rule 18 scenario - PDV gives way to RAM.
Sound and flash 2, bold a/c to port to pass ahead at a safe distance, continuing to monitor until past and clear.
Nothing to stop me going to starboard but I would first have to gather more information. Given nature of operations, it is unlikely that the vessel will be proceeding at a high speed and so crossing her bow would likely be the best option.
What is this?
Actions?
Power driven vessel towing
Length of tow over 200m
Towing vessel probably over 50m LOA
Underway possibly making way
Seen from right ahead/bow aspect
Take a series of compass bearings to ascertain risk of collision. If range decreasing and bearing steady, risk of collision deemed to exist.
Rule 14 scenario - two PDVs head-on
Sound + flash 1, a/c to starboard. Pass at a safe distance, continue to monitor until past and clear
What is this?
actions?
PDV towing an inconspicuous object 25m+ in breadth
Tow length over 200m
Tow v/l under 50m
Underway possible making way
Take a series of compass bearings to ascertain risk of collision. If range decreasing and bearing steady, risk of collision deemed to exist. Being cognizant of the fact that ROC may exist with an appreciable change in bearing given length of tow.
Rule 15 scenario; maintain course and speed, continue to monitor.
No action; sound 5, call master.
Still no action; sound 2, a/c to port to pass clear astern of towed object.
Could also a/c to stbd to pass ahead but given time taken during waiting for action, a/c to port would be most expeditious.
