What rank corresponds to the O-9 designation?

The rank that corresponds to the O-9 designation is Vice Admiral. In the U.S. Navy's rank structure, officers are classified as O-1 through O-10, with O-9 specifically designated for the rank of Vice Admiral. This rank typically involves significant leadership responsibilities, often overseeing large commands, groups, or fleets, and serving in high-level strategic roles within the Navy.

Understanding navy ranks is crucial as they indicate the level of authority, responsibilities, and experience. Vice Admirals are senior to Rear Admirals, both lower and upper half, which correspond to O-7 and O-8, respectively. An Admiral, which corresponds to the O-10 designation, serves as the highest regular rank and indicates even greater seniority and responsibility than a Vice Admiral.