Final answer:
Admiral Elmo Zumwalt was the first surface warrior to hold the office of Chief of Naval Operations before Admiral Jeremy "Mike" Boorda.
Step-by-step explanation:
The first surface warrior to hold the office of Chief of Naval Operations before Admiral Jeremy "Mike" Boorda was Admiral Elmo Zumwalt. Admiral Zumwalt was known for his reforms in the U.S. Navy related to racial equality and modernization during his tenure as CNO from 1970 to 1974. While Admiral Chester Nimitz played a crucial role during World War II as a fleet admiral, and Isoroku Yamamoto was a key Japanese naval commander, it was Admiral Zumwalt who directly preceded Admiral Boorda as a surface warrior in the highest naval office.