The Merit of Paper Chart Back-Ups

[Hud3]

In the Caribbean islands from Vieques to Grenada, I never used paper charts. They could be very inaccurate. So were the electronic charts, since they're all based on the same out-dated input data, some of it from Lord Nelson's time. But the electronic charts were much more convenient than paper as a way to get a picture of what to expect, in general terms, when entering a new anchorage.

The sketch charts in the guide books were more than adequate, along with very careful eyeballing.

[Adelie]

Originally Posted by sneuman

(apologies to Mark. I am having fun emulating his style of post).

Why apologies? Imitation is the best flattery!

[MarkJ]

Hmmmmm. You'll keep!


You're right about the dividers. Damn dangerous! Everytime I open my chart table I stake my finger on them! I get disoriented with the flights of moths escaping!

[osirissail]

For the charts of the Caribbean from the Virgins to Grenada get the CYC chart series. They are quite accurate and available in digital raster format.
They are easy to recognize as the colors are quite different and distinctive and they also contain roads and houses/buildings on land. Like most "private" charts they are very good.

[Therapy]

Originally Posted by Hud3

The sketch charts in the guide books were more than adequate, along with very careful eyeballing.

Anyone scanning them and selling so they can be seen/overlayed on electronic devices?

[osirissail]

Originally Posted by Therapy

Anyone scanning them and selling so they can be seen/overlayed on electronic devices?

Actually some of the older chart kits had Steve Palidus's chartlets in them. But with some of the navigation programs like OpenCPN and Fugawi and a few others you can do your own scans and then import them into the nav program and register them for lat/long, etc. Then they are usable as e-charts.

[Therapy]

Originally Posted by osirissail

Actually some of the older chart kits had Steve Palidus's chartlets in them. But with some of the navigation programs like OpenCPN and Fugawi and a few others you can do your own scans and then import them into the nav program and register them for lat/long, etc. Then they are usable as e-charts.

Amazing.

And beyond my capabilities.

[Jens1]

Originally Posted by Hud3

refering to Hud3 post

That is unfortunately true. The most electronic charts base on processing paper charts. If the paper charts are out-dated the electronic version is that too.
In the ENC (official vector charts) the mariner can switch on an indication called CategoryOfConvidence. The symbols used indicate how much one can trust the information.
Over-reliance of electronic charts, simply based on their brilliant presentation is serious issue.
I discussed that on my website's NAVIGATION section in regard to ECDIS.

[skipmac]

Originally Posted by Night_Sailor

A good point. Practically speaking, in 40,000 sea miles, I am trying to remember if I have seen that. I'll checked the my logs. Weather tends to move pretty quickly, with a cycle of clouds to clear sky's and back as often as during once per watch--that is what surprised me the most about ocean sailing. Of course I avoid hurricanes, bad weather, and sailing near Iceland.

Back when I first started sailing did a nonstop sail from Venezuela to FL. Had planned to stop in St Thomas but was making good time, good winds so went straight through the Virgin Passage and on to Ft Lauderdale. This was 30 years back and don't remember exactly but was about three weeks with solid overcast every day. Finally got a clear sky and horizon at twilight about 40 miles off the Bahamas and got a fix that put me a few miles from my DR position. Of course I had a fix from departure passing the VI so the DR was only 8-9 days old. As I recall it was late fall when we did the delivery.

So, it can happen. One drawback to celestial.

[hellosailor]

Jens-
" The most electronic charts base on processing paper charts." I think you will find that varies radically with the source. Perhaps the electronic charts of Pitcairn Island are made from scanned Admiralty charts 200 years old, but I believe most nations with ongoing hydrographic surveys (like the US) source all their data in electronic form, and the paper charts are just "printouts" of the current electronic data, updated on an ongoing basis.

It really doesn't matter how you navigate--as long as you understand the basis for the entire process. Or, you're lucky.

[barnakiel]

You know, there are old sailors and then there are brave sailors but there are not many ....


;-)))
b.

[Jens1]

Originally Posted by barnakiel

You know, there are old sailors and then there are brave sailors but there are not many ....


;-)))
b.

Independently from where the data of the electronic charts are processed, one back up is better than no back up.
Commercial vessels are going to be completely digital. That indeed underlines the importance of understanding how the electronic charts are produced and the accuracy one can expect.
And it underlines what hellosailor was saying. The user must understand the whole process.

[David M]

Having both is better than having one or the other.