How Current Is Your Chart?

Chris Riley by Chris Riley Updated on July 29, 2019. In nauticalknowhow

An Update on NOAA

Take a look in your chart table and look at the date on the charts that you are using. My guess is that many are two, three, five or maybe even years older. Do you religiously check the weekly Local Notice to Mariners to update your chart for changes in aides to navigation locations, extinguished lights, dredging spoil areas, etc.? To see the online version of Local Notice to Mariners:

The Most Up-To-Date Charts in the World

Over the past several years NOAA (National Oceanic and Atmospheric Administration) has continued to reinvent itself by improving its services to mariners. While just a few years ago paper charts, the only charts available, were updated on a very relaxed schedule. It has been NOAA’s charge to make this happen weekly. In order to do this, new innovations in chart delivery and chart types had to be developed.

NOAA still produces and maintains nautical charts that cover the Great Lakes, the coastal waters of the U.S. and its territories. NOAA’s chart arsenal still includes the traditional paper charts but now go far beyond by introducing electronic charts and other user-friendly products.

Traditional Paper Charts

A lithographic printing process produces traditional paper charts, and although NOAA designs and produces them for printing they are actually printed by the Federal Aviation Administration.

Individual charts vary in physical size and scale to meet specific needs of mariners. For example:

  • Most traditional paper charts are printed on one side of large-format, durable paper.
  • Small-craft charts are pre-folded much like a road map and are tailored for use by the recreational boater.
  • Some traditional charts that cover rivers or canals are created in page format and are spiral bound to form a book.

When a new chart edition is created, it includes the latest nautical information available to NOAA up until the time of printing. New editions are published when one or more changes of navigational importance render the prior printing obsolete. During a typical year, NOAA may create 200 to 300 new chart editions. The edition number and date (month and year of printing) are found in the lower left corner of the chart. The dates of the latest Notice to Mariners and Local Notice to Mariners corrections applied to the chart are also listed.

Print-on-Demand Charts (POD)

NOAA’s Print-on-Demand nautical charts provide the most up to date information available to mariners. These charts are updated on a weekly basis and include all critical chart corrections. NOAA produces these POD charts but does not sell them directly to the public. The POD charts can be obtained through NOAA’s commercial partner OceanGrafix. OceanGrafix has retail agents located throughout the US and overseas.

Print-on-Demand Charts key features:

  • Updated Weekly with critical corrections from Notice to Mariners and other corrections such as wrecks, rocks, and obstructions not yet published.
  • Available Immediately 2-8 weeks sooner than traditional NOAA paper charts.
  • Local Distributors. Printed at multiple sites in the U.S. and overseas. Shipped next day via FedEx.
  • Enhanced Readability . Printed in brighter colors so that the charts are easier to read. Additionally, you can order charts without the Loran grid for enhanced readability.
  • Durable . Available in two durable versions: water-resistant paper (preferred by most mariners) and laminated.
  • Added Value . Useful navigational information, such as tide tables, bridge clearances, and excerpts from the Coast Pilot, is included in chart margins. The information is specific to commercial or recreational mariner’s needs.

You can find a POD retailer here:

(At the time this article was published, the above site was not online. If this happens when you try to access it, check back later to see if this site is back up.)

Raster Navigational Charts (RNC )

NOAA Raster Navigational Charts® (NOAA RNCs) are full-color digital images of NOAA’s entire inventory of paper charts. NOAA provides weekly updates to the RNCs, which are available for free on there website in the BSB format. The BSB format is a compressed raster format used for distributing raster nautical charts by various organizations in North America, such as MapTech and NOAA. NOAA RNCs are official data that can be used in many types of electronic charting systems, including Raster Chart Display Systems (RCDS) and Electronic Chart Display and Information Systems (ECDIS).

Raster files consist of a grid of different-colored pixels (dots). When the pixels are taken all together, they make up a digital image. Each pixel in a raster file is either turned on (you see a dot of color) or turned off (you see a white dot). The pattern of the dots makes up the shape of the features on the chart; the pixels that are turned off make up the white space. If you zoom into a raster chart, you will see all the individual pixels, but the image will become fuzzy and illegible.

Electronic Navigational Charts (ENC)

NOAA Electronic Navigational Charts® (NOAA ENCs) are vector data sets that represent NOAA’s newest and most powerful electronic charting product. NOAA ENCs conform with the International Hydrographic Office (IHO) S-57 international exchange format, comply with the IHO ENC Product Specification, and are provided with incremental updates that supply Notice to Mariners corrections and other critical changes. NOAA ENCs and updates are available for free download. NOAA ENC data may be used to fuel Electronic Chart and Display Information Systems (ECDIS).

In 1997, NOAA began a process of building a portfolio of ENCs that encompass the same areas covered by NOAA’s approximately 1,000 paper and raster charts. The ideal and most accurate way to build ENCs is to recompile the paper chart from all of the original source material. Unfortunately, this process is impractical as it is far too labor intensive. Instead, NOAA ENCs have been compiled from source on those features that are deemed to be navigationally significant. U.S. Army Corps of Engineers’ federal project limits have been captured from large-scale drawings. These precise coordinates of channel limits are being incorporated into the ENC. Likewise; high-accuracy positions are being used to chart U.S. Coast Guard aids to navigation. The paper chart has been the source for the remainder of items.

As of September 2008, 670 NOAA ENCs are available for download. All of the major ports throughout the country now have NOAA ENC coverage. Many smaller scale coastal ENCs that connect these ports have been completed, while some are still in the building process. NOAA plans to continue its ENC building program in the upcoming years.

To download NOAA ENCs go to:

NOAA’s Online Chart Viewer

NOAA’s 1,000-plus U.S. coastal and Great Lakes nautical charts are now viewable here on-line.

Each chart is up-to-date with the most recent Notices to Mariners corrections.  Use these on-line charts as a ready reference or planning tool.  Use NOAA’s printed or digital charts to navigate with on your voyage.

These online charts allow you to zoom in and out and pan left and right and up and down. You can also drag the navigation box in the upper left hand corner to move around the chart image.

NOTE : You should use official, full-scale NOAA nautical charts for real-world navigation. These are available from authorized NOAA nautical chart sales agents. Screen captures of the on-line viewable charts do NOT fulfill chart carriage requirements for regulated commercial vessels under Titles 33 and 46 of the Code of Federal Regulations.

This chart display or derived product can be used as a planning or analysis tool but may not be used as a navigational aid.

Other NOAA Chart Products include:

Pocket Charts The new NOAA PocketChart â„¢ is a special-purpose chart for beginning recreational boaters. Beginning boaters can use the PocketChart to help answer their two most frequent questions: “Where am I?” and “How do I get to…?” This inexpensive, introductory charting product has a miniature NOAA nautical chart on one side, and safety, boating, and educational information on the reverse side. PocketCharts may be purchased for about $6 each from numerous retail outlets serving boaters. NOAA reassembles that PocketChart with the most up-to-date information every time a chart changes.

The chart side is a complete, full-color NOAA chart that has been reduced in scale. (On average, the charts are 34% of full scale.) The primary text is legible, but text that appears small on the full-scale charts is even smaller on these reduced-scale charts. The result is suitable for its intended use as a locator, but is not suitable for real navigation.

To find a PocketChart dealer:

Booklet Chart The NOAA BookletChart â„¢ is an experimental product that you can print at home for free. They are made to help recreational boaters locate themselves on the water.

The Booklet Chart is reduced in scale and divided into pages for convenience, but otherwise contains all the information of the full-scale nautical chart. Bar scales are also reduced in scale, but are accurate when used to measure distances in a BookletChart. Excerpts from the United States Coast Pilot are included. Most chart notes are consolidated on a single page for easy reference. Emergency information for the charted area is printed on the back cover.

BookletCharts for most areas are available now. Download them as Adobe Acrobat files and print them on any ordinary printer. Two-sided printing gives the best results. Staple the pages along the edge to make a booklet. Print the entire chart, or only those pages you need. A broadband Internet connection is advised.

NOTE: During this experimental period, BookletCharts are not being updated every week with Notices to Mariners.

List of Available NOAA BookletChartâ„¢ Downloads:

  • Atlantic Coast
  • Gulf Coast
  • Pacific Coast
  • Alaska
  • Great Lakes

NOAA also produces several other nautical publications. For example, the United States Coast Pilot® is a series of nautical books with a variety of important information for navigators to supplement the nautical chart.




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