Mariner Credentialing

1/10/2018: Important information for sending email attachments to National Maritime Center

The National Maritime Center posted an alert to its website with information for customers sending attachments to NMC through e-mail.

E-mail is a critical way for mariners to communicate with the NMC. This notice is intended to advise stakeholders of the following limitations in the Coast Guard’s e-mail system regarding sending of e-mails with attachments to the NMC:

  • The system will not accept attachments larger than 10 MB.
  • It is highly recommended that attachments larger than 8 MB be split into multiple e-mails.
  • When sending multiple e-mails, please ensure the subject of each e-mail indicates the order of the attachments.
  • The system will not accept compressed (ZIP) files, regardless of size.


E-mails that are larger than 10 MB or that include compressed files as attachments will not be delivered. Furthermore, neither the sender nor intended recipient will be notified of the delivery failure.

We apologize for any inconvenience related to e-mail submissions to the NMC. Any documents exceeding the 10 MB limit should be mailed to:

National Maritime Center
100 Forbes Dr.
Martinsburg, WV 25404

Questions should be addressed to the NMC call center via e-mail to, via Chat, or via phone at 1-888-IASKNMC (427-5662).

This blog is not a replacement or substitute for the formal posting of regulations and updates or existing processes for receiving formal feedback of the same. Links provided on this blog will direct the reader to official source documents, such as the Federal Register, Homeport and the Code of Federal Regulations. These documents remain the official source for regulatory information published by the Coast Guard.

Leave a Reply