[1] Sadler took on the task of consolidating projects begun by Comrie, publishing new tables for use in navigation.
The Second World War soon intervened and the Nautical Almanac Office was moved temporarily out of London to the safer environment of Bath.
[1] Sadler supervised the relocation of the Nautical Almanac Office in 1949 from Bath to the new home of the Royal Greenwich Observatory at Herstmonceux Castle in Sussex.
He increased international cooperation in preparing astronomical tables, particularly with the United States Naval Observatory.
[4] Donald Sadler oversaw the transfer of the Nautical Almanac Office within the Royal Greenwich Observatory from the control of the Admiralty to the new Science Research Council.
[1] Sadler contributed to other scientific societies, including the Royal Institute of Navigation, of which he was president from 1953 to 1955.