The title of HMSAS ( His Majesty 's South African Ship ) was changed to SAS ( South African Ship ) in 1952 , and the Crown in the SAN cap badge was replaced with the Lion of Nassau from the crest of the country 's coat of arms in 1959 , two years before South Africa became a republic .
In 1951 , the South African Naval Forces was renamed to the South African Navy and the ship title HMSAS ( His Majesty 's South African Ship ) was changed to SAS ( South African Ship ) one year later .