Charts

[rumrunner]

For a long ocean voyage.. how do you store your paper charts.

I hate folds in charts ( also dangerous)

Ok, do you sort into portfolos, then hang them on say a half inch piece of dowl, or just place tthem in a draw or round container ( pvc pipe) ?

rumrunner....[?][?][?][?][?]

G'day Brian,

After I lost a very extensive set of charts when my previous boat was holed on Curlew Island, I have become very protective of the replacement ones I am slowly buying back. To ensure these ones are OK I've got a length of plastic water pipe sealed at one end and a screw lid on the other, I can take them by dingy to another boat without worries of being splashed and they are safe from any minor accidents below. They are seperated into states with different colour sheets of light card and prior to leaving are in order of needed usage, but each to their own!

[Chetan]

sorry to sound ignorant but are these regular admiralty charts?

what scale charts would you recommend for coastal cruising and where can such charts be procured?

[Auzzee]

I have all my paper charts in specially manufactured plastic water resistant flat packs. The packs are readily available and hold 20 or more charts. They take a full sized admiralty chart. They are then easily stored in their scores under mattresses. Yohoho Rumrunner. Best wishes David

[Auzzee]

PS..Hi Chetan. Coastal cruising demands the biggest scale practicable for your boat and budget. Obviously the more charts you buy, the more expense you have to incur. The larger the scale, the more easily the navigator can spot hazards. But irrespective of the charts you buy for coastal passages, it is imperative that you have large scale detailed charts for ports you wish to visit. Best wishes. David

[JeanneP]

We have acquired charts from various sources, including photocopies - made by we yachties, made by a few chart suppliers. We've found that storing them flat underneath our bunks was the most efficient way to keep them - in plastic covers as Auzzee states. Rolled up charts were a nuisance to flatten again.

Friends of ours set up a flat chart storage place by attaching a piece of plywood to their headliner and storing the charts there. However, after a few years the accumulated weight of the charts pulled the screws out of the headliner and the whole thing crashed onto the bunk. Fortunately there was no-one sleeping in it at the time.

Some of our experiences:

1. photocopied charts - I sat with colored felt-tip highlighter pens and colored in land, water, sand banks, etc. This made it easier.

2. Storing photocopied charts is a bit of a problem because the toner will come off the charts - we had it stuck to the plastic covers, to other charts, etc. I found that if I placed waxed paper between the charts it protected the charts better, and kept the toner from sticking to the plastic or paper.

3. We always recorded our course on the chart. The best way, since in some places we used the same charts over and over again, was to place a heavy clear vinyl sheet on the chart table under which we put the chart. We then used either dry-erase pen or china (wax) pencil to set our DR and record our position, date, time, etc. This also kept the chart safer from spills and salt spray.

4. We used some pretty old charts, and some charts just haven't been updated in years, so you should verify the datum specified on the chart, and the offset that might be necessary to conform to your GPS position. In some places (Solomon Islands comes to mind), there was up to a mile or two difference between charted position and GPS position! Careful!

Fair winds,

Jeanne

[Chetan]

hi all

thanks for the valuable info

especially the distinction between "large scale = less detail" and "small scale = more detail"

likewise for the tips on storage; the use of the clear vinyl sheet was a good tip

any chance someone could help out with the contact details of a supplier for such "small scale" cruising charts?

regs

chetan

[Chetan]

any (budget) cruisers who can share their experiences with electronic charts?

[JeanneP]

You'll find lots of sources, including sources for inexpensive photocopied charts, by doing a Google search of "nautical charts"

[Carl Spackler]

Re; Photo copy toner.

Art stores, and some craft shops, sell a spray can product that coats and fixes work done in chalk, pencil, etc. It also gives a little waterproof effect.

[lang]

Someone told me (not too long ago), that handheld gps with installed maps are highly inaccurate in asia. His GPS showed that his boat was travelling on land when he was definately on water.

I have not verified if his account was true or was it caused by other factors, such as zooming in to a 3ft area on screen with only 30ft accuracy.

But hh GPS is definately the best choice for me, due to limited boat size and ... budget.

Lang

Preparing to cruise, very soon will be.

Originally Posted by name='Converted Post'

Originally posted by Chetan

any (budget) cruisers who can share their experiences with electronic charts?

[JeanneP]

Originally Posted by name='Converted Post'

Someone told me (not too long ago), that handheld gps with installed maps are highly inaccurate in asia. His GPS showed that his boat was travelling on land when he was definately on water.

I have not verified if his account was true or was it caused by other factors, such as zooming in to a 3ft area on screen with only 30ft accuracy.

We have had the same experience, but it isn't the GPS that's inaccurate, it's the charts that are the problem. Most of them were drawn before the days of GPS, and surveys since GPS have generally been in the US and areas of US influence.

We've used two charts of an area, one US, the other Great Britain, and had a 2 mile difference in the placement of an island (large rock, really, and something we were very anxious to avoid). We chose not to trust EITHER chart and changed our course significantly to be sure we didn't come close.

Some of our charts have "CAUTIONS" stamped on them - "some points on this chart may be displaced as much as one mile."

However, you can in some instances improve their accuracy. First, on charts printed after GPS development you will often find information giving you an offset that you enter into the GPS in the Setup section.

Another correction you can make is the DATUM. Look for "DATUM NOTE" on your chart (I don't guarantee you'll have it - our very old charts don't). It will say something close to "Positions obtained from satellite navigation systems referred to the World Geodetic System **** (WGS-****)[ed. - **** = date]. You must then find the datum section of your GPS and change it to the datum system noted on the chart. (there are quite a few, WGS-1984, WGS-1976, Australia, etc.)

But everyone should understand that as accurate as GPS may be, a great many areas of the world haven't been surveyed since the WW II era when it was more difficult to determine lat/long and only areas of military interest were reasaonably accurately surveyed. And things change.

To blindly follow your GPS plot is a serious mistake that will jump out and bite you at the most inopportune time.

Be careful out there.

Fair winds,

Jeanne