 |
|
01-06-2010, 04:33
|
#1
|
Registered User
Join Date: Jun 2010
Posts: 11
|
What Do People Use to Plot Routes ?
Hello,
Over here in France, to plot routes on ships and know what direction to tell their helmsman/steerer to aim for, people use the Règle Cras ("Cras ruler", invented by Rear Admiral Jean Cras) shown in this picture with my explanations on how it's used:
http://img12.imageshack.us/img12/886...ereglecras.jpg
The nice thing about the Cras ruler, is that it's compact and has no moving parts, so it's pretty long-lasting.
I'm curious to know what sailors use in other countries to plot routes.
Thank you.
|
|
|
01-06-2010, 04:46
|
#2
|
Registered User
Join Date: Apr 2004
Location: Toronto
Boat: CS36Merlin, "La Belle Aurore"
Posts: 7,557
|
Parallel rules.
__________________
Rick I
Toronto in summer, Bahamas in winter.
|
|
|
01-06-2010, 04:56
|
#3
|
Long Range Cruiser
Join Date: Dec 2007
Location: Australian living on "Sea Life" currently in England.
Boat: Beneteau 393 "Sea Life"
Posts: 12,820
|
Quote:
Originally Posted by littlebigfred
Règle Cras ("Cras ruler", .
|
My system is though as being crass too: I use the chartplotter or Laptop charting OpenCpn or Google earth.
Mark
|
|
|
01-06-2010, 04:56
|
#4
|
Registered User
Join Date: Jun 2010
Posts: 11
|
Thanks for the reply. Does it mean that people use a parallel ruler + a protactor (if there's none printed on the map)?
How to use parallel rulers
|
|
|
01-06-2010, 06:47
|
#5
|
Registered User
Join Date: Mar 2007
Location: Santa Cruz
Boat: SAnta Cruz 27
Posts: 7,198
|
I use my mouse--very quick, convenient, and accurate.
|
|
|
01-06-2010, 06:50
|
#6
|
Registered User
Join Date: Aug 2009
Location: South coast of England, moving around a bit.
Boat: Long range motor cruiser
Posts: 750
|
Quote:
Originally Posted by MarkJ
|
I'd say that was practical.
__________________
The message is the journey, we are sure the answer lies in the destination. But in reality, there is no station, no place to arrive at once and for all. The joy of life is the trip, and the station is a dream that constantly out distances us”. Robert Hastings, The Station
|
|
|
01-06-2010, 07:44
|
#7
|
Registered User
Join Date: Apr 2004
Location: Toronto
Boat: CS36Merlin, "La Belle Aurore"
Posts: 7,557
|
Quote:
Originally Posted by littlebigfred
Thanks for the reply. Does it mean that people use a parallel ruler + a protactor (if there's none printed on the map)?
How to use parallel rulers
|
Charts do have a compass rose on them. Some parallel rules have degree marks on them like a protractor, just put the bottom line on a meridian and the top line on the same meridian with the angle you want.
__________________
Rick I
Toronto in summer, Bahamas in winter.
|
|
|
01-06-2010, 11:12
|
#9
|
Registered User
Join Date: Apr 2004
Location: Toronto
Boat: CS36Merlin, "La Belle Aurore"
Posts: 7,557
|
Quote:
Originally Posted by littlebigfred
|
Yes, that's the type.
__________________
Rick I
Toronto in summer, Bahamas in winter.
|
|
|
01-06-2010, 11:39
|
#10
|
Registered User
Join Date: Jun 2010
Posts: 11
|
Interesting. I'll have to play with those when I get the chance. Thanks for the education.
|
|
|
01-06-2010, 11:57
|
#11
|
CF Adviser
Join Date: Oct 2007
Boat: Van Helleman Schooner 65ft StarGazer
Posts: 10,280
|
Welcome to CF littlebigfred….
Most of the commercial mariners have been trained to use a pair of navigational triangles like this:
Amazon.com: Weems & Plath Marine Navigation Protractor Triangle with Handle: Sports & Outdoors
The main reason other than accuracy and speed in doing the examinations is that in preparing charts for parallel indexing, using 2 Triangles is very quick to draw safety perpendiculars off your course lines, without having to shift or walk the rulers.
Very quick and accurate once you get used to them and as Rick says, you dont bother with the compass rose but read off the meridians
|
|
|
01-06-2010, 12:10
|
#12
|
Registered User
Join Date: Jun 2010
Posts: 11
|
I've seen those things but Google didn't return videos on how they're used while sailing to know what direction to take.
What is "parallel indexing"?
|
|
|
01-06-2010, 12:49
|
#13
|
Registered User
Join Date: Apr 2006
Posts: 4,413
|
Plotting routes is hardly necessary. You certainly do need to be prepared to navigate complex channels or landfalls and leaving ports. But for the most part you have enough time to go below and select a way point for your next mark, enter into the GPS and get back to watch keeping and sail trim.
Route planning is a creation of the geeks who had no understanding of sailing a boat. You certainly need to keep a fix and your plotter does that.
If you plot onto a chart, parallel rules, and dividers are all you need.
|
|
|
01-06-2010, 12:57
|
#14
|
Armchair Bucketeer
Join Date: Oct 2006
Posts: 10,012
|
|
|
|
01-06-2010, 13:09
|
#15
|
Moderator

Join Date: Mar 2009
Location: Denmark (Winter), Cruising North Sea and Baltic (Summer)
Boat: Cutter-Rigged Moody 54
Posts: 35,232
|
Don't forget you've got to correct for variation and deviation, if you're steering with a magnetic compass. Also any set of current.
I am a great believer in having and using paper charts, but here they suck compared to putting the plotter's cursor on your destination and pressing "go to". Presto, you've got a true bearing and range, and you also know your true course over ground compensated for absolutely everything.
We do have a Portland plotter on board, but it is more a curiosity.
|
|
|
 |
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|