According to International and Danish maritime regulations, all vessels must carry updated charts and nautical publications to be considered seaworthy.
The sinking of the Titanic in 1912 prompted a movement towards improved maritime safety. The international convention SOLAS (Safety Of Life At Sea) was founded in 1914 as a direct response to the Titantic catastrophe. When the IMO (International Maritime Organisation) was formed, SOLAS and maritime safety were placed under the organisation's jurisdiction.
SOLAS Chapter 5 defines the requirements for nautical charts and publications. As Denmark has ratified SOLAS, the relevant requirements and stipulations have been integrated into Danish maritime law.