Do you need to post your passport mmd?

[QUOTE=john;14166]Yes, Norleen L. Schumer of MaritimeLicensing.com sent us this from the USCG:[/QUOTE]

Only domestically.

Note the last line on the updated letter (that was probably already online when the original post was made here).

“As a security measure, mariners should not post their credentials while the vessel is visiting foreign ports.”

https://www.uscg.mil/nmc/announcements/pdfs/posting_mmc_on_vessel.pdf