Collection consists of envelopes cacheted (stamped or imprinted) with the names and logos of ships in the Canadian, British and American naval and maritime service collected by John M. MacFarlane by sending requests to the various vessels and asking them reply using the envelopes he provided. With few exceptions, the materials were posted between 1977 and 1980.

Most of the envelopes have ship's mail room cancellations. A few of the envelopes have captain's privilege franking (signature of a ship's official rather than a stamp). Also included are relevant items such as pictures or postal cards showing the vessels or other records related to the vessel (usually brochures/pamphlets).

The materials were originally housed in 3-ring binders. The records were removed from the binders and placed in archival folders during processing by the Archivist.

MacFarlane organized the envelopes into sections including Icebreakers, Patrol Cutters, Aircraft Carriers, Sounding Vessels, Frigates, Canadian Government Ships, CNAVs, WPBs, WLBs, UK Merchant vesseks, and Royal navy vessels. These original groupings have been maintained.