A few nations distribute their ENCs without using encryption; all ECDIS systems are able to access and display these ENCs without ?Chart Permits?.
Usually the ENCs are provided on CDs. If a new set of ENCs Base CDs was delivered, that CDs will replace all previous Base and Update CDs which then can be disposed of. New update CDs delivered in future will be based on the new Base CDs. If a collection of Update CDs arrive the vessel, always only the latest one needs to be applied.
