Explanation: For vessels equipped with GMDSS (Global Maritime Distress and Safety System) emergency equipment, FCC regulations (specifically Part 80) outline specific testing requirements. While *at sea*, daily and weekly operational checks are mandated to ensure critical systems like DSC, SARTs, and EPIRBs are constantly ready for distress. However, when a vessel is *in port*, the regulations do not require the same frequent testing schedule. The primary concern is ensuring the vessel's emergency equipment is fully functional *before it departs* for a voyage. Testing immediately prior to leaving port ensures readiness for the upcoming journey, as the vessel transitions from a safe, supported environment to one where self-sufficiency is paramount. Frequent testing while idle in port is not required by regulation, as the immediate need for distress communication is diminished and unnecessary wear on equipment can be avoided.