Interpreting ColRegs

[Pelagic]

In 1960 they changed the wording from “moderate speed in restricted visibility” to “safe speed..at all times” when shallow water effects and longer stopping distances with higher tonnages became more problematic


Rule 6 Safe speed

Every vessel shall at all times proceed at a safe speed so that she can take proper and effective action to avoid a collision and be stopped within a distance appropriate to the prevailing circumstances and conditions.

In determining a safe speed the following factors shall be among those taken in to account:

(a) By all vessels.

(i) the state of visibility;

(ii) the traffic density including concentrations of fishing vessels or any other vessels;

(iii) the maneuverability of the vessel with special reference to stopping distance and turning ability in the prevailing conditions;

When can a speed be judged as being “too low” for the prevailing conditions?

(iv) at night the presence of background light such as from shore lights or from back scatter of her own lights;

This is for picking out navigational lights….. how would “high humidity” thru your own back scatter affect visibility?

(v) the state of wind, sea and current, and the proximity of navigational hazards;

(vi) the draught in relation to the available depth of water.

Does everyone know what “squat” is? And the effects on steering? (e.g.: yacht entering a marina)

(b) Additionally, by vessels with operational radar:

(i) the characteristics, efficiency and limitations of the radar equipment;

(ii) any constraints imposed by the radar range scale in use;

(iii) the effect on radar detection of the sea state, weather and other sources of interference;

(iv) the possibility that small vessels, ice and other large floating objects may not be detected by radar at an adequate range;

(v) the number, location and movements of vessels detected by radar;

(vi) the more exact assessment of the visibility that may be possible when radar is used to determine the range of vessels or other objects in the vicinity.

In determining safe speed there is a general rule of thumb accepted by the courts that you should be able to stop in ½ the available range of visibility, but that all other factors should be taken into account including time needed to assess the situation.

[unbusted67]

Originally Posted by Boracay

As a general thought I have been wondering if the ColRegs are more of an enforceable code of conduct than a set of rules.

In racing they are clearly rules, there is a single body to enforce them, and an expectation that there are going to be winners and losers.

However for the rest of the marine world they are more of an "enforceable" guide.

There are multiple bodies that may enforce them, and any one of them could "rule" differently to another.

I totally agree with this. It seems like most times commercial captains aren't exactly following the rules to the t. I have been aboard many a time where a captain will pass starboard to starboard when he should have gone port to port. Or when was the last time you heard someone use sound signals in a crossing or overtaking situation? How many smaller vessels carry all of the appropriate lights and day shapes in case they find themselves constrained by draft or NUC. I think the rules are there for captain's to know what they are liable for. I know I will catch flack for this but hey.

[Bash]

Originally Posted by unbusted67

I I know I will catch flack for this but hey.

I agree. I think that much of the reason for this is that the gap between the regulations and technology grows by leaps and bounds. I'm required to carry a bell, but not a VHF. I'm required to have flairs, but not an EPIRB. I'm required to signal my COLREG status by day shapes, but not by AIS.

So, when someone complains that no one motorsailing flies an inverted cone, we must consider the fact that this may indicate a lapse in the COLREGS rather than common practice.

[Pelagic]

Nobody follows the rules to the T because they were never intended to be so restrictive that common sense and good seamanship would take a back seat.

Knowing how the courts have interpreted the Rules as I explained in my post #25 is just a useful guidance for those who are trying to quantify a decision and action.

For me, I always put myself on the other ship/yacht’s bridge and assume they are having a bad day or consider me a total idiot. I then try to make things easier for them.

[jackdale]

Pelagic

I agree wholeheartedly.
That is what rule 2 is all about.

Jack

[nigel1]

Squat is the term used to describe the increase in a vessels draught due to reduced under keel clearance, usually starts to take effect when the UKC is less than the vessels draught.
It will also cause the vessels trim to change, usually by the bow, but some vessels will experience an aft trimming effect.

In relation to safe speed, squat is a considerable consideration, the fast the vessel, the more the squat, roughly speaking, double the speed, the squat effect increases fourfold.

In narrow channels, the effect of squat is increased due to the confines of the banks.
Squat is also affected by the vicinity of other vessels, two vessels passing close to each other squat will increase, and taking into consideration vessel interaction, loss of control of the vessel is highly probable
The problem is that squat effects the steering and has likened to steering in porridge.
Two vessels passing close in a narrow channel, they should, both reduce speed to reduce the effects of squat and interaction, especially in an overtaking situation where the passing time is long, there have been many cases where the vessels have been drawn together in such circumstances.


Too low a speed can also be considered a fault if it causes a vessel to lose steerage way, and I would imagine that a vessel dawdling along in a channel could also be considered at fault if this action led to a collision.

Stopping in half the distance of visibility. In the pre 1972 colregs, the term Moderate speed was used rather than safe speed. Nowadays, with radar and other aids, such as AIS, vessel traffic control etc, the need to proceed at a speed which enables a vessel to stop in half the vis distance is no longer applicable in every case. It does put the onus on a vessel which detects by radar another vessel, and determines that a close quarter situation is developing, to reduce her speed.

[Pelagic]

Great answers Nigel… (I would have marked that 100%) …lol…

There has actually been awards given against a vessel that slowed down so much when being overtaken in a narrow channel, that she could not hold her course.

Small sailing yachts rarely have a problem with going too fast…. Except when maneuvering inside a marina.

The issue, especially with monohulls in a large following sea and wind, is maintaining a straight course in order to show steady intent when being overtaken…. But that is in the next Rule

From my commercial training I always log on Star Gazer, when I have reduced down to a "safe speed".... especialy in reduced visibility

Does anyone else do that?

[Laidback]

Just to reiterate the International Regulations for Preventing Collisions at Sea are not some toothless rules, but actually provide for the seizure of a vessels that contravene the regulations and also provision for fines ranging from $1,000 >>>$5,000 for each offense - including imprisonment for up to a year. I served as jury foreman in Hong Kong in a case involving obstruction by Coastal Trader of a Aircraft Carrier.

[Pelagic]

Laidback... would love to hear the details.... I know those waters well

[donradcliffe]

I totally agree that they ought to fire the old farts who are in charge of the colregs and start all over again with rules which reflect today's technology and conditions. Anyone who wants me to spend the night banging on a bell when at anchor in fog is back in the stone age.

I rmember reading the findings on a recent freighter-sailboat collision in the English Channel--22 knots was considered a safe speed in thick fog, because the freighter had its ARPA radar on. Unfortunately, the radar didn't include the effect of the current...

[donradcliffe]

Whoops, that one went out into cyberspace half finished. The primary cause of the collision was found to be that the sailboat misinterpreted its radar, and decided to stop in front of the freighter instead of standing on.

[nigel1]

Originally Posted by Pelagic

From my commercial training I always log on Star Gazer, when I have reduced down to a "safe speed".... especialy in reduced visibility

Does anyone else do that?

Yep, thats something in my standing orders when commercial, and on the sail boat, also the same. Last January coming round Dover was caught in a really heavy snow squall at about midnight, it was that heavy that the radar was virtually of no use, could not see didly squat. Called Dover Harbour just to check on ferry traffic, and hoved to to wait it out before crossing the narbour entrence

[Lodesman]

Originally Posted by Pelagic

Does everyone know what “squat” is? And the effects on steering? (e.g.: yacht entering a marina)

How fast do you enter marinas?

In determining safe speed there is a general rule of thumb accepted by the courts that you should be able to stop in ½ the available range of visibility, but that all other factors should be taken into account including time needed to assess the situation.

I don't think this is really practical for large commercial vessels, nor for any vessel in restricted vis.

From my commercial training I always log on Star Gazer, when I have reduced down to a "safe speed".... especialy in reduced visibility

Do you mind explaining what Star Gazer is?

[Pelagic]

Originally Posted by Lodesman

Do you mind explaining what Star Gazer is?

My sailboat

[Pelagic]

Originally Posted by donradcliffe

I totally agree that they ought to fire the old farts who are in charge of the colregs and start all over again with rules which reflect today's technology and conditions. ...

Donradcliffe, the International Rules are an evolution designed to adjust to changing technology without loosing track of early solutions that sometimes may be needed, so I think those old farts do a pretty good job except that there is quite a time lag in new implementation for political reasons, which is not under their control.

When taking the radar simulator and ARPA courses there is a great deal of time spent on developing techniques to properly adjust and ground stabilize the large IMO compliant (28” screen) radars for zero visibility and how to develop an effective bridge management team to have 2 working radars monitoring traffic at different ranges so as to maintain a fast speed that in the past would have been unheard of.

One radar display is doing early detection and assessment between 12m to 8m, while the other interconnected display is ranging down from 8 to 4m performing any avoiding action…then scaling down even further to monitor a close quarter situation.

Having said that,…in the example you gave, I am quite sure the courts criticized the freighter for failure to maintain an effective CPA and as to your comment about the sailboat’s failure to stand on…. We will get to that after the appropriate rules (in restricted visibility) have been reviewed, since this is a great example of different interpretations.

Incidentally Don, the sailboat’s radar confusion in a close quarter situation with a big ship is a common problem because the skipper has only one small radar display and he is ranging out and in, without fine tuning the gain.

When he gets into a tense close quarter situation, he often forgets to turn down the gain and the radar return bounces off different parts of the ship, giving him confusing mini arpa details. The trick is to get proficient at manually tuning your small radar in a close quarter situation, so as to receive a consistent return and arpa data. That is why I recommend all skippers practice that in good visibility

Those fairly subtle warnings are what the old farts are referring to in Rule 6b (i) to (v).