The New York World's Fair of 1939-40 attracted the attention of Scouts in the United States.  Many thousands visited the Fair, while other Scouts participated in the Service Corps.

The Boston Sea Scout Division organized a special World's Fair Cruise of Sea Scout vessels.  The boats sailed from Boston Harbor through Sandwich, Massachusetts enroute to New York Harbor.  They stayed at Sandwich from August 17-20, 1939.  A commemorative cachet was printed to mark the event.  A special line was added to allow the Sea Scout Ship (S.S.S.) to add their name.  These envelopes were then hand-cancelled in the local post office.

Some envelopes were signed by members of the crew, such as this envelope from the S.S.S. Spindrift II, with Skipper "R H Brown" signature.