Final answer:
To obtain or verify Merchant Mariner credentials, personnel should contact the NMC, part of the USCG. The NMC handles the issuance, while their MMC verification tool supports real-time credential checks.
Step-by-step explanation:
Personnel inquiring about obtaining Merchant Mariner credentials or verifying the validity of a mariner's credentials should be directed to the National Maritime Center (NMC), which is part of the United States Coast Guard (USCG). The NMC is responsible for the issuance and maintenance of credentials necessary for mariners to be employed on U.S. vessels. To initiate the process of obtaining Merchant Mariner credentials, one would need to complete the appropriate applications, undergo a physical examination, and provide proof of sea service among other requirements. Moreover, the procedure for verifying the validity of a mariner's credentials can also be facilitated through the NMC's website, as they offer an online verification tool known as the Merchant Mariner Certificate (MMC) verification tool. This system allows for real-time, up-to-date verification of the credentials, ensuring that a mariner is authorized to perform their duties under the required standards.