Paquebot is an international agreement about Ship Mail that was developed in the days when international travel was all done by sea. Most journeys took at least several days so it was usual that the travelers onboard would want to write and send letters. Delivering mail posted at sea required co-operation from all different international postal services so they had to set up a system. It was agreed that, while in the open sea (neutral territory), each ship is territory of the country that owns her. Therefore a letter written on a British ship can use a British stamp, even when the British ship is far away from her home country. When the ship reaches a port, the officer is able to pass the mail to the local post office whatever the country and the mail will be delivered without any extra charge. In the 1890s, the Universal Postal Union (UPU) introduced "Paquebot" postmarks which had a common datestamp and the word “Paquebot” written by hand or stamped on to the envelope. Of course, this has very interesting implications for cover collectors.
[QM2 Cover] Paquebot postmarks are not only evidence that a cover has been carried onboard a ship and posted at sea. They are also very collectable postmarks in their own right. Unfortunately, when we tried to arrange Paquebot postmarks in 2004, we were told by Royal Mail and Cunard that although the principals of sending mail by ship remain the same, Paquebot postmarks are no longer in use. This QM2 cover with “posted at sea” cachet tries to recapture the feel of the Paquebot covers.