Tag Archives: Navigation

NOAA opens its catalog of nautical charts


More than 1,000 U.S. Coast Guard nautical charts have been released for public use at no charge.

What started out as a three-month pilot program by the National Oceanic and Atmospheric Administration has become a permanent service. The free charts, which are offered in PDF format, are especially valued by recreational boaters.

During the trial period, nearly 2.3 million charts were downloaded, according to Rear Admiral Gerd Giang, director of NOAA’s Office of Coast Survey.

“To us, that represents more than two million opportunities to avoid an accident at sea,” Giang said. “Up-to-date charts help boaters avoid groundings and other dangers to navigation, so our aim is to get charts into the hands of as many boaters as we can.”

If you know the name of the waterway you wish to explore, the fastest way to get a chart is to search the list of available PDFs.

To help users zero in on the charts they need, NOAA has created a website called the Interactive Chart Locator. From there, one can view an image of the chart; download a PDF version of the entire map; or choose a blown-up version with numerous maps of the same area, known as a “booklet.”

NOAA also has begun offering its Raster Navigational Charts, a composite of all the charts formatted for zooming in on a specific location. That is especially useful for viewing on a computer screen or mobile device. Free software and viewers from third-party sources also are listed on the RNC webpage.

NOAA’s Office of Coast Survey is the nation’s nautical chartmaker, according to information provided by the agency. Created by President Thomas Jefferson in 1807, the office updates charts, surveys the coastal seafloor, responds to maritime emergencies and searches for underwater obstructions that pose a danger to navigation.

The Coast Survey’s Twitter handle is @NOAAcharts. A blog — noaacoastsurvey.wordpress.com — provides information about the agency’s ongoing activities.

Charts, tides and currents just a click away

When I need a nautical chart for the Puget Sound area, I’ve begun to click on a website called DeepZoom, a site that takes you into an animated wonderland of tides and currents.

Software developer Jay Alan Borseth of Seattle is using Microsoft’s DeepZoom technology to weave together hundreds of charts and maps, allowing the reader to quickly scan and zoom to the location of interest. The whole thing runs on Silverlight.

Unique features about the website are not the static maps but the ability to watch changes in tides and currents. Pick a location, type in the date and set the duration of time you wish to review. Use the slidebar to set the clock for checking on tides and currents at a specific time. Or click the start button to play through the animation for the sequence you have chosen.

How fast you move through time can be changed by adjusting the rate.

If you zoom out far enough to see the entire United States, you can even watch the sun and moon move across the sky.

Jay told me that he believes the Puget Sound region is fairly complete, especially for the nautical elements. Other parts of the U.S. and the world are still works in progress, however. He also envisions integrating other types of charts and maps for planes, trains and automobiles. Some of these elements are already accessible by clicking at the top of the page.

The idea for animating the currents came to him as he was reviewing charts for boating, he said. He expects the basic website to stay free for users, but he may develop a mobile application that could be commercialized.

“It’s about halfway through,” Jay told me, “but it is momentarily on hold.”

He explained that he is working on other software applications now occupying his time, but he hopes to get back to this project.

If anyone knows of other web-based charts and graphs that are particularly interesting, please feel free to share them.