Getting back to using NAAIRS for South African family history research: a common mistake amongst first-time users of the index is placing two search terms on one line of the search form. Detach surname from forename and enter the words on two separate lines of the form. Also make use of the Beginning and Ending features at the foot of the form to give a date parameter for your search: this helps limit unnecessary hits, especially if the surname is commonly-found.
If you’re looking for a deceased estate file for your ancestor, remember that if he died in South Africa comparatively recently, say within the last 30 years, the estate reference would not be reflected on the index e.g. in Natal deceased estate files up to 1974 are shown on NAAIRS.
There are two non-archival databases on NAAIRS: the Bureau of Heraldry (HER) and Gravestone Inscriptions recorded by the Genealogical Society of South Africa (GEB). Under the MAN database are National Registers of Manuscripts (NAREM) and Photographs (NAREF). On these you can search libraries and museums as well as archival repositories. NAREM could lead you to a shipboard diary: first prize would be one written by your own forebear but accounts by contemporary travellers can be useful. NAREF could help you locate a photograph of an ancestor.