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David_Old_Jersey · 25-03-2011, 00:59

Quote:

Originally Posted by Therapy

I have seen one with only sticks and string but I cannot find it.

I bet folks never thought the stick based navigation discussion would be so protracted...........

doug86 · 25-03-2011, 05:11

Quote:

Originally Posted by windships

New Electronic charts do not have the shore based details that papercharts have.

A raster scan chart is an exact duplicate of a paper chart, as if you ran it through a copier machine. Explain how could it not have the same details?

jackdale · 25-03-2011, 08:20

Quote:

Originally Posted by doug86

A raster scan chart is an exact duplicate of a paper chart, as if you ran it through a copier machine. Explain how could it not have the same details?

Interestingly, raster charts are only approved for use with ECDIS when paper charts are carried as back up.

ActiveCaptain · 25-03-2011, 08:24

Quote:

Originally Posted by jackdale

Interestingly, raster charts are only approved for use with ECDIS when paper charts are carried as back up.

Actually, it's much more interesting that the IMO rules changed in January 2011 and they no longer require paper chart backups. Now the backup can be electronic. It's allowed to be paper too although it's no longer required.

And that's what I've been saying...as of late 2010, things have changed.

jackdale · 25-03-2011, 08:46

Good example of how far off electronic charts can be over at SN.

Isla Isabel, Mexico - SailNet Community

Isla Isabel is 1.5 miles from where it should be.

jackdale · 25-03-2011, 08:56

Quote:

Originally Posted by ActiveCaptain

Actually, it's much more interesting that the IMO rules changed in January 2011 and they no longer require paper chart backups. Now the backup can be electronic. It's allowed to be paper too although it's no longer required.

And that's what I've been saying...as of late 2010, things have changed.

Does that also apply to raster charts as back up?

Quote:

The Maritime Safety Committee, at its seventieth session (7 to 11 December 1998), adopted amendments to the performance standards for Electronic Chart Display and Information Systems (ECDIS) to include the use of Raster Chart Display Systems (RCDS).
These amendments permit ECDIS equipment to operate in two modes: .1 the ECDIS mode when ENC data is used; and .2 the RCDS mode when ENC data is not available. However, the RCDS mode does not have the full functionality of ECDIS, and can only be used together with an appropriate portfolio of up-to-date paper charts.

IMO | Charts, ECDIS

ActiveCaptain · 25-03-2011, 09:01

Quote:

Originally Posted by jackdale

Good example of how far off electronic charts can be over at SN.

There are multiple paper chart examples now along the Atlantic ICW that are dead wrong. One off the Alligator River in NC will set any 5.5' vessel aground. The other one only has safe water by going directly over a charted island of land. I know that shoals change frequently but you'd think an island on the ICW would stay put for a few years at a time.

Is there anyone who seriously believes that paper charts are more accurate than electronic ones? At best, they have the same inaccuracies. In general, electronic charts have more chance of being updated and distributed so at least you'll have more current inaccuracies...

Where do you think the paper charts come from? Do you think there's some cartographer with a water color set and an easel painting them?

ActiveCaptain · 25-03-2011, 09:07

Quote:

Originally Posted by jackdale

The Maritime Safety Committee, at its seventieth session (7 to 11 December 1998)

13 years is multiple lifetimes in the technology world. They probably wrote that up on a Windows 95 PC and saved it to floppy disk.

I wasn't saying that raster charts meet the regulations for IMO. I know they don't. Raster charts are more in the domain of recreational boating. I just thought that it was more interesting that IMO no longer requires any paper backup as of this year.

jackdale · 25-03-2011, 09:10

Jeff

By using paper charts with a handbearing compass, a plotter, a Mark I eyeball and a Mark II brain; you can get a fix and a RELATIVE position.

jackdale · 25-03-2011, 09:11

Quote:

Originally Posted by ActiveCaptain

I just thought that it was more interesting that IMO no longer requires any paper backup as of this year.

When using an ECDIS, not an ECS.

ActiveCaptain · 25-03-2011, 09:19

Quote:

Originally Posted by jackdale

By using paper charts with a handbearing compass, a plotter, a Mark I eyeball and a Mark II brain; you can get a fix and a RELATIVE position.

Same thing with electronic charts. I've turned off the GPS and done pure DR and anchor position monitoring with the electronic display. It's way easier because you can "write" things on the electronics and just delete them later. It also does a lot of manual operations like bearings for you in more user-friendly ways.

It's really nice on the iPad because it has a built-in compass. Taking advantage of that, you point the iPad at a target and the chart rotates to make that target heads up. That makes it quite nice to mark and measure things. Point to another target and get another bearing. Getting a numeric heading reading takes some of the guesswork out of using a hand compass too (is that one tick or two?).

I'd like to see some additional tools on some of the electronic charting to assist with this type of thing. I seriously doubt it'll come out on anything major though because most people would never use the capabilities. I'm working on some anchoring software and have no intention on putting them in because it'll just confuse most users.

jackdale · 25-03-2011, 09:23

Jeff

My Google skills have failed; can you point me to the January 2011 IMO announcement.

Thanks

ActiveCaptain · 25-03-2011, 10:23

Quote:

Originally Posted by jackdale

My Google skills have failed; can you point me to the January 2011 IMO announcement.

I tried using Google on: imo ecdis 2011 paper

Seemed simple enough - you can dig for the actual IMO regulations. One nice reference that popped up right away is:
http://www.westpandi.com/Publication...DIS-and-BNWAS/

Note that some changes like "may" substituted for "must" make a major difference in regulations. You'll find that paper charts now have the "may" word in place - they may be used as a backup, instead of they must be used as a backup.

jackdale · 25-03-2011, 10:57

Quote:

Originally Posted by ActiveCaptain

I just thought that it was more interesting that IMO no longer requires any paper backup as of this year.

Thanks for that link. That helped.

Not sure that "any" is the correct word. Paper chart back ups are still required for RNCs and are to be the principal means of navigation when used with RCDS.

Quote:

An ECDIS may use RNCs, but when ECDIS is employed in this way IMO requires the system to be used together with an appropriate folio of up to date paper charts for the voyage. Likewise, when a RCDS is in use, paper charts will remain the principal means of passage planning and position monitoring regardless of the type of electronic chart being used.

Some paper back up may required.

The Canadian Regulations are consistent with the IMO regulations.

In reality, I would not imagine that the police or Coast Guard would pay much attention. However, the pesky insurance companies might; as might courts.

I still ask the schools I work for to provide me with the charts.