NAVPAC & Compact Data 2016-2020 Version 3.4

NavPac and Compact Data (DP330)
With increased awareness of the vulnerabilities associated with relying on electronic positioning systems to provide the navigator with their location, NavPac and Compact Data is the celestial navigation software produced by Her Majesty's Nautical Almanac Office at UKHO.  This can provide a valuable back up and an independent check of position.
A new version of NavPac is available for existing users of NavPac as a free download.  Users need to have registered their copy of NavPac 3.4 before they can access the new version.  Please note that this is not a new edition.  It is an interim release during the lifespan of the current 2016-2020 version (V3.4).
The key features of the new version can be viewed at http://astro.ukho.gov.uk/nao/navpacfour/features.html
Version 4.0 is available to download from http://astro.ukho.gov.uk/nao/navpacfour  Please note that the file is an executable which some firewalls may restrict.  Please contact your IT department in the first instance if you are not able to download the software.The purpose of this publication is to provide navigators and astronomers with simple and efficient methods for calculating the positions of the Sun, Moon, navigational planets and stars over several years to a consistent precision with the aid of a pocket calculator, personal computer or laptop.​​