Rolling ruler or Parallel plotter?

[StuM]

Originally Posted by El Pinguino

How did his name get onto the ridgeedij plotter in the photo that I linked to?... small print lower left...

A bit more googling turned up this 2011 Yaching Monthly article by Goode.:
http://www.marinepublications.co.uk/shop_pdfs/9.pdf

In it he says:
"That’s why, about 20 years ago, I developed the plotter that, among its other applications, uses practically sized ‘units’ instead of ‘real’ sea miles to reduce the process of constructing a tidal vector to the bare minimum. One line and a couple of dots can produce a course to steer on any scale of chart in less than half a minute – as shown on the opposite page for a short (approx 2 nm/20 min) cross-tide run."

So I'd guess that the scale along the edge of that plotter is the key to why his name is on it. (labelled :"Boat Speed/Tide Speed knots" on that plotter instead of the more common "Inch/Units" or "Cms")

[meatservo]

Originally Posted by Pelagic

Most professional navigators were trained to use Triangles... Much faster more accurate and stable on full sized charts

This video will explain why and you will never go back


https://youtu.be/t02n1VDSzYI

Dude!

That Rocks! Thank You!


meatservo

[StuM]

Originally Posted by El Pinguino

Looks to me like 'tide system devised by John Goode' which sounds like a bit of a stretch to me.... you didn't need to be billy the Boy genius to see that it could be used to do tide vector thingos....

We're posting over each other.

Yep, The "tide system" is his scaling along the edges.

[El Pinguino]

All he did was put cms all round rather than inches on the long side and cms on the ends... that is an improvement as easier to work with.

Most of them for sale still seem to have inches.....

[barnakiel]

A navigational triangle: me, my mate, my boat.

The other triangle is called the French triangle ;-))))))

Summmmmeerrrr tiiiimmmeeeee!

Love,
b.

[hellosailor]

The obverse of the E6B plotter [ https://en.wikipedia.org/wiki/E6B ] is what sets it apart from "just" course plotters. But of course, a circular slide rule can be intimidating. Damned handy if you know how to use them though. The batteries never seem to leak or explode.(G)

Chartbooks *used* to be inherently inaccurate in the US, back when they made by photographing the NOAA/USGS charts and reprinting them. They suffered from simple errors like the camera sometimes not being perfectly aligned, so the image would "keystone" and distort. That was the price you paid for saving $500 a shot, and that was rent money.

Nowadays? We Colonials are lucky enough to *own* the chart data, and since the chartbooks are faithful renderings made from the digital chart data, same as the source, there should be no stigma attached to them. Besides, a half degree error harbor hopping coastwise, isn't at all as critical as it would be in transoceanic jaunts.

[waterman46]

Neither. Most efficient is a protractor device. It has the compass rose on one end and a rotating straightedge extending out about a foot. You can mark the local magnetic variation on the reference pointer so you won't have to do the correction each time. No searching for compass roses on the chart. This device is light and flexible, its not the one whose picture has been posted in this thread. That one is also a protractor but it is way too big and heavy. I have used all of these methods and none can compare.

Sorry I don't have a picture and don't know the brand and its on my boat about 2000 miles away.

[Dockhead]

As others have suggested -- Portland Plotter is the tats! If you have grid lines on your chart (and you should), then it completely eliminates the need to walk off your course line, which is very awkward on a small nav station and all the more in a rough seaway!

If anyone is interested in the history of this excellent device -- despite the name, it seems to have actually been invented by the French more than a century ago, and should properly be called a "Breton Plotter"!

https://www.youtube.com/watch?v=1gYeR10549k

[StuM]

Originally Posted by Dockhead

A

If anyone is interested in the history of this excellent device -- despite the name, it seems to have actually been invented by the French more than a century ago, and should properly be called a "Breton Plotter"!

Guess you missed Alan Mighty at Post #29 in this thread
http://www.cruisersforum.com/forums/...ml#post2440770

[Dockhead]

Originally Posted by StuM

Guess you missed Alan Mighty at Post #29 in this thread
http://www.cruisersforum.com/forums/...ml#post2440770

Indeed I missed that excellent post!

[matt w]

Originally Posted by Pelagic

Most professional navigators were trained to use Triangles... Much faster more accurate and stable on full sized charts

This video will explain why and you will never go back


https://youtu.be/t02n1VDSzYI

That guy is brilliant! "Oh no, it won't reach!". Thanks for sharing that link, I see how useful triangles are and will use them from now on.