Mail between St.Thomas and St.Croix was often sent by mail schooner "Vigilant" that departed the Chralotte Amalie harbor every Tuesdag and Friday eveningg. It arrived in Christiansted early the next morning, weather permitting, It and other mail
carrying ships were subject to the following regulation dated December 2, 1901:
The "Vigilant" letterbox was heavily used by the public who could deposit mail on it after the local post office had closed. St.Thomas used a special four-ring cancel for
mail arriving with stamps that had not been canceled. the ring cancel would be used on the stamp(s) and than the St.Thomas date cancel would be struck on the back . the four ring cancel is commen on DWI stamps demonstrates just how extensive this praticce
was. It is, however very rarely seen on bisected mail. The study only located three such items, one being an envelope.
Somtimes a "C" would also be used to indicate the mail was from Christiansted. Christiansted
Post Office did not have a similar arrival cancel. Mail that had beeb deposited in the letterbox while the ship was at St.Thomas would have been canceled "Christiansted" with a date on the stamp since the DWI post office required all stamps to be canceled.
Not all mail between St.Thomas and Frederiksted was routed via Christiansted. The post office also routed mail on ships sailing directly between the two locales.