The NOAA S57 vector chart system promises a revolution for all mariners navigating US waters. With the advent of SetSail-MaxSea V9.2 you now have free access to these charts (in fact 9.2 Yacht is shipping with the complete database as of late April 2002). Wanting to find out more about the process by which NOAA creates these new charts, and the schedule on which the S57 charts are being completed, I called Dave Myers, the Production Manager for Electronic Navigation Charts (called ENCs) at NOAA. After a long and fascinating discussion, I came away very impressed with the process being used.<\/p>\n
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The process by which S57 charts are created is laborious and time consuming. Because of funding constraints and congressional mandates, the initial conversion work is done by outside contractors (whether this is time- or cost-efficient is another story). The conversion starts with what is called a “continual maintenance raster”. This is a digitally stable image-analogous to a print negative, on which all key navigational information is kept.<\/p>\n
The contractor takes the data and runs it through a software program called “Caris”. This program enables the cartographer to convert the data from its raster form to the S57 vector format. However, this is not an automatic process. In essence, the data is transferred by using a mouse, with hand\/eye coordination being critical. The data is then “georeferenced” (i.e. positioned with geographic coordinates) to make sure it is in exactly the right place.<\/p>\n
When the initial conversion process is completed, the contractor adds Army Core of Engineer dredging data, and the latest wrecks and obstruction information to the vector chart database. The completed chart is then returned to Dave Myers’ cartographers for a quality check.<\/p>\n
How thorough is this QC analysis? Dave says that they check every single data point on each chart, a painstaking and time-consuming process. His direct quote was, “We check every square inch of every chart for accuracy”. Each cartographer can do between 10 and 12 charts per year-that’s something like a full month per chart on quality control. Dave has 17 cartographers on his staff, so this means a maximum of 200 charts per year through the pipeline. Once the new S57 chart is accepted, it goes into the continuing maintenance process for updating as conditions warrant. And here’s a cool aspect of this process-because the entire catalog will fit on a single CD-ROM, it will be relatively simple for SetSail to update (and add) charts as new data becomes available-keeping costs and therefore the selling price to a minimum-or you may be able to download updated charts from the Internet for free.<\/p>\n
The initial goal of the conversion process is to get the 40 most heavily used commercial ports going ASAP. By September of this year (2002) this process will be complete (as of our conversation in mid-May the following ports have not yet been completed: Port Hueneme, CA; Puget Sound; Boston; Portland, Maine; Wilmington, North Carolina; the Great Lakes, Columbia River; and Hawaii).<\/p>\n
Dave says the current schedule is to have the coastline of the US (including Hawaii, the Virgin Islands, Alaska, and Guam) completed in 2005\/6. At present, in addition to the major ports, there are many minor ports now covered (for example, much of Long Island Sound, Southern New England, and the Chesapeake Bay are on the SetSail-MaxSea version 9.2 S57 CD-ROM).<\/p>\n
What does all this mean for those of us in the SetSail community? First, if you are a U.S Taxpayer, this is the second program (the first is the Marine Prediction Center) for which we are getting good value for our taxes. Second, in the areas where charts are available,you now have FREE access to the most accurate charts in existence. And, as new charts become available, you will be able to download them from the Internet.<\/p>\n
We’ll be staying in touch with Dave Myers and his team at NOAA to see how the schedule is coming-and keep you apprised of what we find.<\/p>\n","protected":false},"excerpt":{"rendered":"