Who is McKinley Moran from Cannery Row and what is their importance?

McKinley Moran is a deep-sea diver, Moran formerly lived in Cannery Row, making a fortune accepting government stipends for finding dumped liquor during Prohibition and bribes from bootleggers for not finding it. Moran earns enough to marry and drifts away. He offers Mack an opportunity to complain about matrimony, later revealing he is once married.