Final answer:
The Sea Service Deployment Ribbon is awarded after 12 months of sea duty, including at least one deployment of 90 consecutive days. It is a recognition of extended sea service, especially for those who serve in combat zones where the required period may be shorter.
Step-by-step explanation:
The Sea Service Deployment Ribbon (SSDR) is awarded to personnel assigned to U.S. homeported ships and deploying units, as well as units of the Marine Corps operating forces. To be eligible for this award, personnel must complete 12 months of accumulated sea duty. This period must include at least one deployment of 90 consecutive days. If the deployment is to a combat zone, the required period can be shorter. This ribbon recognizes the sacrifice and service of military members during extended operations at sea, reflecting the commitment and readiness of the Navy and Marine Corps.