One of the earliest navigational databases was Integrated Data Store (IDS), which was developed by Bachman for General Electric in the 1960s.
Navigational database programming thus came to be seen as intrinsically procedural; and moreover to depend on the maintenance of an implicit set of global variables (currency indicators) holding the current state.
The declarative nature of relational languages such as SQL offered better programmer productivity and a higher level of data independence (that is, the ability of programs to continue working as the database structure evolves.)
Many of these systems introduced data manipulation languages which, while far removed from the CODASYL DML with its currency indicators, could be understood as implementing Bachman's "navigational" vision.
Database systems that support navigational APIs often use internal storage structures that contain physical links or pointers from one record to another.
Such composite identifiers are found in computer file names (/usr/david/docs/index.txt), in URIs, in the Dewey decimal system, and for that matter in postal addresses.
A current example of a popular navigational API can be found in the Document Object Model (DOM) often used in web browsers and closely associated with JavaScript.