Changing course

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Myrtonos

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I know there are rules about vessels altering course, such as the stand on vessel maintaining course and speed, and signalling ones intent to alter course and speed. First of all, is there any definition of changing course?

Is a sailing vessel said to be changing course if it is changing direction relative to the direction of the wind?
 

southkogs

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Yes, "tacking" (and jibing, I suppose) is a course change.
 

dthx

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Any time you change your Direction with respect to the Compass.....you change your "course".
Period.
 

Myrtonos

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First of all, what compass directions do you mean, magnetic or gyro. The direction of the wind changes from time to time with respect to either set or compass directions, and with it, the direction of a sailing vessel changes.

Also, what about vessels on a narrow channel. Are those following a curve in the channel (such as a bend in the river) legally changing course, or not?

As roads are relatively narrow and follow paths, a vehicle on it is turning if leaving the path of a marked centre line. Does a similar concept apply to vessels on inland waterways that are also relatively narrow and follow paths?
 

fhhuber

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If the pointy end of the boat is aimed at point A on shore... and you change that.... you changed course.

Doesn't matter if its a gyro compass or a magnetic... if the needle isn't staying on the same number/point on the dial (or for electronic ones, if the numbers change).... you changed course.

The main idea is... if you do something unpredictable and cut the other guy off.... you might be buying the other guy's boat, despite it being at the bottom of the lake.

The rules of right of way for boats is really simple... if you can see the other guy's red light on the bow (or could if it was night and it was on)... he pretty much has the right of way. And if you are coming up from behind, its bad form to ram him in the butt.

Finally: Its better to yield than argue right of way while your boats sink.
 

Scott Danforth

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My suggestion is to take the boaters safety course. this is taught after the first 20 minutes.
 

Myrtonos

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If the pointy end of the boat is aimed at point A on shore... and you change that.... you changed course.

Maybe on a lake or a sea, but what about following a bend in a river?

Doesn't matter if its a gyro compass or a magnetic... if the needle isn't staying on the same number/point on the dial (or for electronic ones, if the numbers change).... you changed course.

What if one compass changes while the other doesn't?

The rules of right of way for boats is really simple... if you can see the other guy's red light on the bow (or could if it was night and it was on)... he pretty much has the right of way. And if you are coming up from behind, its bad form to ram him in the butt.

I have heard that the rules for a narrow channel are different from those on a body of water which doesn't follow a path.
 

southkogs

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All of the above - including the river and compass questions - qualify as course changes. I've never heard the term applied to boats, but I'm assuming navigators would use it like they do in airplanes: vector. It's a math term that describes space and speed between two points, and also what a vehicle is on relative to an X,Y and Z axis in motion.

Even your car technically changes "course" on a curvy road ... but the road is designed to accommodate those course changes.
 

Myrtonos

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All of the above - including the river and compass questions - qualify as course changes. I've never heard the term applied to boats, but I'm assuming navigators would use it like they do in airplanes: vector. It's a math term that describes space and speed between two points, and also what a vehicle is on relative to an X,Y and Z axis in motion.

Are you saying that course change could have a number of different meanings?

Even your car technically changes "course" on a curvy road ... but the road is designed to accommodate those course changes.

But legally it is going straight. Does anyone here know how turning is defined in their local highway code? I presume that one is turning if leaving the path of a marked centre line. If you cross the marked centre line, it is either a left or U-turn. If the turn does not cross the path it is a right turn expect at an intersection of two-one way streets when turning into a street where all traffic already on it approaches from the right.

Does a similar concept apply in any jurisdictions to vessels on inland waterways that follow paths? I know even these don't have lane markings, but I would guess there is a similar concept to a marked centre line.
 

fhhuber

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MOD EDIT: I heard you the first time. He's not a troll.
 
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southkogs

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Are you saying that course change could have a number of different meanings?
In a sense that's probably a little bit true ... but only if you're really wanting to dig into the technical weeds.

Penny-wise / Pound-foolish in my opinion.

But legally it is going straight. Does anyone here know how turning is defined in their local highway code?
And actually that kind of helps punctuate things: you don't need as much training to navigate a car as you do a boat. A car has references that a boat (or airplane) doesn't have.

So you don't really have an apples to apples comparison going.
 

Myrtonos

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In a sense that's probably a little bit true ... but only if you're really wanting to dig into the technical weeds.


And actually that kind of helps punctuate things: you don't need as much training to navigate a car as you do a boat. A car has references that a boat (or airplane) doesn't have.

So you don't really have an apples to apples comparison going.

In fact, you don't actually need much more training to navigate a land vehicle than to walk. The references that manually steered vehicles have are basically the same as what pedestrians have.

But remember that boats on narrow inland channels, such as rivers, do in fact have similar references, one reference is the flow of rivers, this being in a fixed direction. Only at sea or on a large lake is one without such references. But even at sea, there are some references that may still help punctuate things, one being the wind in case of sailing vessels. Another is ocean currents, I have heard of currents that follow the same path over long periods of time.
 

southkogs

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Still doesn't work out the same way ... wind and currents aren't consistent. Asphalt is much more so.

Though, stick yourself in a jeep in the middle of a desert, and now you've got a situation that is more similar to being a on a boat in the ocean.
 

Myrtonos

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But nevertheless they do affect sailing vessel priority.

In case of a vehicle in the desert, you aren't dealing with the dynamic properties of water.

But the point is that a vessel on a narrow channel, especially inland, is also in a similar situation to a vehicle on the road. Except for lines on the ground, all the references are there. So, in that case, is a concept similar to the official definition of a turning vehicle. Would a vessel entering leaving the path of a marked channel be legally the equivalent of a turning vehicle?

I have heard that the rules on a narrow channel are different from open water. For example I did read that precedence first belongs to vessels going against the current, then with the current, then cross river ferries.

Sometimes, I think that marked channels exist even on open water, for example between the edge of a bay and the largest river that flows into it. A vessel following the path of the channel might be considered to be going straight and one entering or leaving to be turning.
The body regulating that bay could decide to make vessels crossing the marked channel keep clear of any vessel following it if all else is equal.
 

dingbat

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Sail boats, under sail, have right of way over a power boat at all times. Course changes, etc. don't apply.

You can go out in the middle of the fishing fleet on the troll and do figure eights thru them.
 
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fhhuber

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"Sail boats, under sail, have right of way over a power boat at all times. Course changes, etc. don't apply.

You can go out in the middle of the fishing fleet on the troll and do figure eights thru them. "

and get run over....

You having the right of way does not make the other boat able to turn or adjust speed in order to avoid you.

I've seen a sailboat protesting an aircraft carrier going out to sea get in front of it... and get squashed. it takes 5 miles to stop the 93,000 ton behemoth.

Go ahead... help Darwin and insist that you have the right of way.
 
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Myrtonos

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Sail boats, under sail, have right of way over a power boat at all times. Course changes, etc. don't apply.

Let's say a powered and a sailing vessel are both approaching at right angles to each other, at the same speed. In that case, the sailing vessel must maintain course and speed, and the powered vessel must slow down, alter course to the port, or both.
This is where the definition of course and speed come into it. Because the sailing vessel must maintain its legal course. Apparently the legal course, in open water, is defined according to compass bearing, but that means that the course of a vessel might differ according to whether a magnetic or gyrocompass is used. It is well known that the magnetic and geographic north south axis are out of line. A magnetic compass practically always points in a different pair of opposite directions than a gyrocompass points, and the deviation between the two also varies between different parts of the world.

You having the right of way does not make the other boat able to turn or adjust speed in order to avoid you.

I've seen a sailboat protesting an aircraft carrier going out to sea get in front of it... and get squashed. it takes 5 miles to stop the 93,000 ton behemoth.

Go ahead... help Darwin and insist that you have the right of way.

In fact a typical sailing vessel would be required to give way to any vessel that large.
 

southkogs

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Man - you'd make a good legislator or defense attorney :lol:

Navigational rules and definitions allow for and account for the difference between compass readings. I'm more familiar with it in airplanes, but regardless the rules of navigation handle that minutia. The more complex the navigation the more critical the rules and differences become.

Also - don't forget: ultimately, the skipper of any vessel is bound to do anything in their power to avoid a collision. Backing up Dingbat: a sailboat has right of way enough that they can go wreak havoc in a larger vessels course. However, the sailboat skipper could be acting recklessly inciting both a legal and "Darwinian" consequence (Huber's point), that really overrides the whole bloomin' debate.
 

fhhuber

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What he is.... is a total troll.

He asks a question like a noob... argues with all answers and then professes to be an expert.
 

Myrtonos

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Navigational rules and definitions allow for and account for the difference between compass readings. I'm more familiar with it in airplanes, but regardless the rules of navigation handle that minutia. The more complex the navigation the more critical the rules and differences become.

True or false? The rules for narrow channels, especially inland waterways, are already different from open water. Rules that are possible and do work in a narrow channel might not work on open water.

Say a vessel is defined to be altering course if leaving or entering the path of a marked channel and in other places is altering course if changing compass bearing.

That aside, how do navigation rules allow for variations in compass reading? A good example is this. If a vessel with a magnetic compass heads true north or true south for, say, a thousand miles, the compass will move considerably but with the vessel still heading in the same geographical direction. Is it legally altering course?
 
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