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The VDU patches below will update certified libraries on Edition 20 to 08/23.

* 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.

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*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    N/A NtM
A2720410 Port Clarence, Alaska N/A   Windows
       2.5 KB
N/A -
A2720460 Point Hope to Kukpowruk Pass, Alaska N/A   Windows
       182.6 KB
N/A -
A2720470 Point Lay to Peard Bay, Alaska N/A   Windows
       4.7 KB
N/A -
A2720480 Harrison Bay to Skull Cliff Vicinity, US N/A   Windows
       5.3 KB
N/A -
A2720483 Brownlow Point to Harrison Bay, Alaska N/A   Windows
       4.4 KB
N/A -
A2720486 Camden Bay to Demarcation Bay, Alaska N/A   Windows
       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
       721 Bytes
N/A -
A2720493 Approach to Paulatuk Harbor, Canada N/A   Windows
       548 Bytes
N/A -
COA27A Cape Kellett to Discovery Point, Canada N/A   Windows
       1.3 KB
N/A -
COA27B Norton Sound to Bering Strait, United States N/A   Windows
       301.4 KB
N/A -
COA27C East Siberian Sea, Russia N/A   Windows
       881 Bytes
N/A -
COA27D Chukchi Sea, Russia N/A   Windows
       701 Bytes
N/A -
COA27E Anadyrskiy Zaliv, Chukchi Sea, Russia N/A   Windows
       1.8 KB
N/A -
COA27F Anadyrskiy Zaliv, Russia N/A   Windows
       401 Bytes
N/A -
COA27G Demarcation Point to Amundsen Gulf, Canada N/A   Windows
       1,006.2 KB
N/A -
GEN27A East Siberian Sea and Anadyrskiy Zaliv, Russia N/A   Windows
       9.0 KB
N/A -
GEN27B Bering Strait, Chukchi Sea, Beaufort Sea N/A   Windows
       454.8 KB
N/A -
GEN27C Beaufort Sea, Canadian Arctic Ocean N/A   Windows
       2.9 KB
N/A -
H2720400 Nome Harbor, Alaska N/A   Windows
       1,020 Bytes
N/A -
H2720486 Bernard Harbor, Alaska N/A   Windows
       422 Bytes
N/A -
H2720490 Trent Bay, Canada N/A   Windows
       833 Bytes
N/A -
H2720491 Tuktoyaktuk Harbor, Canada N/A   Windows
       955 Bytes
N/A -
H2720492 Police Point, Wise Bay and Summers Harbor, Canada N/A   Windows
       674 Bytes
N/A -
H2720494 Pearce Point Harbor, Canada N/A   Windows
       403 Bytes
N/A -
H2720495 Tysoe Point, Canada N/A   Windows
       468 Bytes
N/A -
H2720496 Sachs Harbor and Jesse Harbor, Canada N/A   Windows
       1.0 KB
N/A -