Searching for Information on My Father William Hugh Yorke Who was Born IN 1918 and Died Poosibly IN 1996

My father had two brothers, Leonard and Vivien, one of whom was the postmaster in Umtata and two sisters, Lulu and Yvonne. My dad was in the South African Navy, posted on Robben Island and Simonstown. He was married to Laurika Christina Yorke, nee Short and after her death to Josephine ? Dad was an avid lawn bowler in Sea Point