Isn’t there a John McCain?
USS John S. McCain (DDG-56)
This warship was originally named after John S. McCain, Sr., and John S. McCain, Jr.,[2] both admirals in the United States Navy. John S. McCain, Sr., commanded the aircraft carrier USS Ranger, and later the Fast Carrier Task Force during the latter stages of World War II. John S. McCain, Jr., commanded the submarines USS Gunnel and USS Dentuda during World War II. He subsequently held a number of posts, rising to commander-in-chief of the United States Pacific Command, before retiring in 1972. These men were, respectively, the grandfather and father of Vietnam War Navy captain and later Senator John S. McCain III.[4]
On 11 July 2018, just 1 1⁄2 months before he died, at a rededication ceremony, Senator John McCain was added as a namesake, along with his father and grandfather.[5]
https://en.wikipedia.org/wiki/USS_John_S._McCain_(DDG-56)