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The VDU patches below will update certified libraries on Edition 20 to 20/24.

* To download individual libraries or patches, right-click on the link and choose 'Save Target As' (for IE) or 'Save Link As' (for Netscape). To download multiple files at once, use the checkboxes to select the files, and click the 'Download' button at the bottom of the list. Once the files have been downloaded, the user must use Winzip 9.0 or earlier editions to extract from the .zip files.



*Rows highlighted below in this color are cancelled libraries since the latest New Edition.*
*Rows highlighted below in this color are new libraries available with the latest New Edition.*

IMPORTANT: As of 15 November 2021, NGA's Maritime Safety Office no longer supports DNC VDU UNIX patches. If you have questions or concerns please contact NGA via the Maritime Quality Feedback System (MQFS)

Number Name Download
full library
Download VDU Patch
Download VDU Patch 
Cancelled or
New Libraries
     N/A NtM
A2720410 Port Clarence, Alaska   Edition 20
       822.4 KB
       390.9 KB
N/A -
A2720460 Point Hope to Kukpowruk Pass, Alaska   Edition 20
       1.5 MB
       231.6 KB
N/A -
A2720470 Point Lay to Peard Bay, Alaska   Edition 20
       2.0 MB
       539.2 KB
N/A -
A2720480 Harrison Bay to Skull Cliff Vicinity, US   Edition 20
       3.5 MB
       1.3 MB
N/A -
A2720483 Brownlow Point to Harrison Bay, Alaska   Edition 20
       3.4 MB
       4.4 KB
N/A -
A2720486 Camden Bay to Demarcation Bay, Alaska   Edition 20
       1.6 MB
       3.3 KB
N/A -
A2720490 McKinley Bay and Eskimo Lakes, Canada N/A   Windows
       1.1 KB
N/A -
A2720492 Approach to Police Point, Canada N/A   Windows
       719 Bytes
N/A -
A2720493 Approach to Paulatuk Harbor, Canada N/A   Windows
       546 Bytes
N/A -