Final answer:
A sailor earns a Navy service stripe after completing one year of continuous active service, signifying their dedication and experience in the Navy.
Step-by-step explanation:
A sailor is qualified to wear one Navy service stripe under the condition of completing one year of continuous active service. This stripe is a visual representation of the sailor's experience and commitment to serving in the United States Navy. A service stripe is not awarded for completing basic training, advanced technical training, or upon promotion to Petty Officer First Class. It specifically acknowledges the duration of service.