“Jack” is the name given to the “Flag” flown on a small vertical spar (pole) at the stem or on the bowsprit of a warship.
E.M.C.
Barraclough, the internationally
renowned vexillologist writes ‘although at first ‘Jacks’ were flown from
the mast-head of a ship, it soon became the practice to fly them from
the ‘sprit-mast’ which was fixed to the bowsprit. It was often been
thought that the “flag” is called a “Jack”
because it flies from the ‘Jack-staff’, but actually the ‘staff’ is
called a “Jack-staff” because the “Jack Flag” flies from it. Likewise,
the British “Union Flag” is most often wrongly referred to as “Union
Jack”.
Most countries use the diminutive of their National flag as ‘Jack’
Scandinavian countries State flags and Jacks are 'swallow-tailed' or 'split' at the fly.
Some countries have/had ‘historic’ or other special 'flag' for use as ‘Jack’ at sea.
The Great Star Flag 1837
An
1818 act established that the Great Star Flag include a star for each
state and 13 stripes. Capt. Samuel C. Reid, a naval hero of the war of
1812, recommended arranging the stars into one 'large Star pattern', a
common design in the 19th. century.
Greece has two Flags, one with the white ‘Greek Cross’ on blue field for use as ‘Jack’ at sea and the other with 'nine
horizontal stripes of blue and white and to the upper side of the
flagpole, there is a white cross on a blue background’ for use as
‘Ensign’
The U. S. Coast Guard Ensign and Jack
The badge has the motto ‘Semper Paratus’ (Always Prepared) and the date ‘1790’. The post card commemorates the 175 th. Anniversary of the U.S. Coast Guard.