What does "blackshoe" signify in naval terminology?

In naval terminology, "blackshoe" primarily refers to sailors who serve in surface warfare, as opposed to those who are aviators (often referred to as "brownshoes" due to the color of their flight boots). This terminology delineates the difference between personnel based on their respective roles and environments within the Navy.

Sailors identified as "blackshoes" typically hold positions directly associated with the operation and management of surface vessels, which includes a variety of operations onboard ships. While the term also contemplates the aviation rate for enlisted personnel, it is essential to understand that it emphasizes the distinction of those who serve on ships versus those who serve in aviation. Thus, both aspects of the correct answer capture the essence of "blackshoe" sailors, making the combination of Choices A and C the most comprehensive understanding of the term within this context.