Captain Walter Parker commanded Olympic from September 1928 to the end of 1929. He always had the highest praise for the ship and felt a special lot for her. Parker died in 1935 during the auction of Olympic's fittings. He did not therefore have an especially long life. His earlier career I don't really know, but I do know that he had been in charge of the liner Homeric before 1928.
I'm led to believe Capt Parker's grave is located at Brookwood Cemetery, Woking, Surrey--perhaps less well known than the other Titanic connections located there.
Paul