Walter Daw was born on 29 September 1901, the son of William and Emily Daw. He was married to Nellie Daw and lived at Torquay, Devon.
He joined the Royal Navy as a Boy Signalman in 1916 and served in the light cruiser HMS CARDIFF. He entered the submarine branch in October 1926 and served in HMS L52 followed by a period on the China Station in HMS PROTEUS, ODIN and OSWALD. Returning from China in 1938 he joined HMS STURGEON in January 1938 and then HMS NARWHAL in May 1940.
He is commemorated on the Plymouth Naval Memorial.