USCG Coast Guard has issued an update.  Actually, this MSIB confirms that there has been no change in the mask requirements for persons traveling on vessels or at transportation hubs (sea ports).

Transportation hubs include sea ports (e.g. passenger terminals, cargo handling facilities, and other shoreside facilities that provide transportation of person or cargo).

• Mariners on “Non-passenger- carrying commercial vessels operated by a team of mariners who all live on the vessel” are exempt from wearing a mask.
• A mask will still be required when the vessel receives persons who are not a part of the team of mariners that live on the vessel.
• Though the CDC is no longer requiring mask wear in outdoor areas, operators of conveyances and transportation hubs, at their discretion, may require masks to be worn in outdoor areas.
• Vessel operators must continue to require all persons onboard to wear masks when boarding, disembarking, and for the duration of travel, unless they are located in outdoor areas of the conveyance (if such outdoor areas exist on the conveyance).
• Operators of sea ports must require all persons to wear a mask when entering or while indoors on the premises.

Additional guidance is found in the full MSIB.