He was the serving CINCPAC during the Gulf of Tonkin Incident, the event which largely precipitated the United States' involvement in the Vietnam War.

During World War II, he commanded the destroyer USS Boyd in the Pacific Theater, earning two Silver Stars.

His brother, Lieutenant Commander Thomas F. Sharp (USNA class of 1935), was reported lost on May 13, 1943 when his submarine USS Pickerel was sunk during its seventh combat patrol of the World War II Pacific campaign.

Sharp's views on U.S. strategy in the war, namely massive military action, differed sharply with the Johnson administration's preference for a gradual buildup of forces.

After suffering a fall in October 2001, Sharp's health steadily declined until he died on December 12, 2001, at his home in San Diego.