Proper chart fix notation

[jonjo]

These forums were boring this morning so I surfed off to brush up on my navigation skills.

I will be sailing with soeone who is RYA evening course trained and I decided it is time to adopt a proper notation for marking fixes and positions on my charts. The Canadian Yachting Association delivered the required internet page. Do UK yachtsmen use the symbols in the graphics on the following page?

http://www.sailing.ca/learnmore/education/nav/CoastalNav.shtm

 

[Phoenix of Hamble]

Nope...

not what I was taught....

I always use the 2 ticks, 2 feet, that the course to walk....... or in plain english, your course made good is the one with two dashes..

As for fixes... the circle around the intersect... yes (but with 3 bearings)

The EP.... a triangle and dot

DR is just a short line at right angles to the course steered

 

[graham]

i think your best bet is to get an RYA approved book on navigation.

Have a look then spot the errors in the replies you will get here.(Theres at least one glaring one allready)

Most public libraries have a shelf of sailing/navigation stuff.Our library has it in the sport section.

I allways find it a bit off putting sailing with someone who has just done a course.being usually singlehanded I dont normally stick to the standard format.

 

[Phoenix of Hamble]

Oh come on Graham.... It must be me that you think has made a mistake... you can't leave me hanging like that... it all look OK to me at a review......

 

[Lifeboat]

"The RYA Book of Navigation" ISBN- 0-7136-6322-7 £12.99

Great book & it covers all of the nav area.

 

[graham]

Re: DR at right angles to heading?

Doesnt Dead Reckoning involve plotting a position from heading and speed/time with no allowance for tide?

 

[Phoenix of Hamble]

Re: DR at right angles to heading?

Well I wondered if thats what you meant... Yes you are right....what I actually meant by a "short line at right angles" was a short line of perhaps 5mm intersecting the course steered at a distance detrmined by the speed travelled... which is exactly how you plot a DR.... I was commenting on the notation used... and thats how I notate a derived DR position...
.

 

[graham]

Re:I see what you mean know!

Yes we both agree ,Sorry I misunderstood what you meant.

 

[Phoenix of Hamble]

Re:I see what you mean know!

No problem...

Its frightening how easy it is to not read what was typed, or more usually, not type what you mean!... the spoken word carries much more detail... I'm sure thats where many of the arguments on this forum come from....

 

[gandy]

Re:I see what you mean know!

NAS, what do you use for a waypoint? and for a predicted EP? I assume that these need to be distinct from actual EP and Fix symbols, so that you can see where you think you vs where you really are vs where you predicted you'd be.

Textbooks generally show these only in isolation - ie the chartwork for working a course to steer, but not what it looks like half-way through the passage with real fixes and EPs added for part of the journey.

Does any of that make sense?

Tony S

 

[Guest]

As memory serves ...

Actual position fix = circle round the point that are crossed bearing lines / distance arcs etc. that produced the fix.
EP position fix = a triangle around the Estimated position dot produced by the course / speed / tide etc. (It was also common for a smart sod to actually write EP next to it ...)
DR position = the lines crossed for speed and course with out any circle / box / traingle etc. around the poiint of cross ... often with DR written next to it ....

I never heard of a line of 5mm crossing the course line .... and never heard about the 2 lines crossing the course line also ...... Commercial shipping notation of a Course line to steer .... line drawn and a parellel line with arrow in direction - in the mid part of the line the course in Degrees true suffixed T .... and if a Mag compass jobbie - Magn course in brackets next to it with suffix M .....

Maybe doesn't agree with RYA - but many a merchantman survived with it .... !!

 

[peterb]

[ QUOTE ]
The Canadian Yachting Association delivered the required internet page. Do UK yachtsmen use the symbols in the graphics on the following page?

http://www.sailing.ca/learnmore/education/nav/CoastalNav.shtm

[/ QUOTE ]

I do have a problem with the Canadian system. They show what we would call the tidal vector as "C-D = anticipated current and leeway". C is shown as the DR position.

Now I've always been taught that the water course is obtained by applying the leeway as a change of angle to the the DR course. This gives a new position (which seems to have no given term or name) from which the tidal vector can be applied to get the EP. Somehow the Canadian system has lumped the leeway and the tidal drift into one line, and I can't see how they can do it. Of course, they may do it in the same way that I've been taught, and their "C-D" may be purely illustrative. But in that case I find ther drawing a bit misleading. Any one else with any comments?