For The Radar Book
For Local Knowledge 
For GPS Instant Navigation
Amendment patches for Shipwrite Marine Maps

The Radar Book

Note - These errata apply to the first edition only. The errors have been corrected in the 2nd Edition of The Radar Book.

Page 3

The MV Stockholm was a Swedish ship, not Norwegian.

Pages 11 to 15

In the process of enhancing the radar display images for the book, errors have been introduced into the images as indicated below:

Figure 1-7 In the screencapture, numeric values of 90.0oR and 0.169 NM are given for the position of the cursor, but the cursor is not visible in the image.

Figure 1-9 In the screencapture, numeric values of 62.5oR and 1.119 NM are given for the position of the cursor, but the cursor is not visible in the image. Also the EBL has been rotated to a position that is not consistent with the numerical read-out.

Figure 1-11 The cursor and the VRM circles were removed in order to simplify the image but the numerical VRM indication remains. In Figure 1-13, the VRM indication shows that the VRM is outside the display.

Page 27, Figure 1-24 

The caption refers to "Left" and "Right".

Should refer to "Upper right" and "Lower right".


Page 81, Middle Text Box

The text in the text box has been cut short. It should read as follows " ‘Radial thickness’ means the thickness of a ‘pip’ or other image on the display measured from the center of the display to the edge."


Page 164, Figure 9-6

The caption to the right has been cut off short. The last sentence should read, "The land echo does not rotate, but with the change in course, it now follows a different RM line as well."


Pages 211 and 221

According to the American Practical Navigator, "aspect" means the relative bearing of own ship from target ship, measured 0o to180o port (red) or starboard (green). This means that when the aspect is 76o red, you are viewing the target ship from 76o on its port side. Therefore, in a practical sense, the definition of "aspect" at the bottom of page 211 and on page 221 is also correct.


Page 212, Fig A-9

The aspect is actually 73o.


Page 213, Figure A-10

The aspect is actually 114o.


Page 213, Figure A-11

The arc of the aspect has been incorrectly drawn. It should lie between the TM of the target A’ and the bearing line from the A’ to the center of the maneuvering board.


Page 215, Caption for Figure A-13

"Course at 12:39" should read "Speed at 12:39".


Pages 218, 219, Minimum Range and Minimum Range Resolution

The theoretical limits for minimum range and range resolution are a result of the characteristics of the pulse length, but the practical limits also are related to the resolution of the display, and the degree of anti-Rain Clutter applied. Consequently the actual specified values differ from the theoretical values given in the table on page 217.


Click here to view the Errata Sheet for the first edition of The Radar Book in PDF format. 

Local Knowledge--A Skipper's Reference


Page 82

The values provided in the example do not match the plotted values in the graphic on Page 83. Replace the text on Page 82 with the attached PDF.

Pages 130 - 133

With the recent change to Vessel Traffic Services in British Columbia, the map of Vessel Traffic Services Zones needs to be updated. Please view the  attached PDF.

GPS--Instant Navigation--2nd Edition

Note on GPS Accuracy Standards: 
In spite of the formal specifications for GPS Accuracy, our research shows that in many cases, consumer GPS receivers may be capable of resolving positions to 10 meters (33 feet) or less. Also, we have observed less short term fluctuations in positioning than expected. Previous to May 1, 2000, Selective Availability was the primary source of GPS error. The amount of Selective Availability [SA] applied to the satellite signals varied rapidly, and consequently produced rapidly shifting apparent positions. However, now the primary source of GPS error is ionospheric  and atmospheric interference. Since the ionospheric influences change in value much more slowly than SA, the result is that GPS positioning fluctuations will vary over longer periods--hours instead of minutes or seconds.  
(November 25, 2000)








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Last updated February, 2016