Le Sémaphore de Marseille was a newspaper founded in 1827 and, in addition to being the oldest in this French port, it was also the longest running, as it was published until 1944. The newspaper provided a wide range of maritime and commercial information, as well as details on the economic activity of the port. Among all this content, the most relevant for the PortADa research project is the information on ship arrivals in Marseille.

The data was obtained from the Intendance Sanitaire de Marseille, the institution responsible for registering each arriving vessel. This type of information appeared in every issue of the newspaper throughout its publication history, forming an uninterrupted record of traffic through the Port of Marseille. This makes Le Sémaphore de Marseille the most consistent and valuable source—among other newspapers and periodicals in Marseille—for the project period, from 1850 to 1914.

The information on ship arrivals is highly structured and remains unchanged throughout the period under study. It is also encoded, in the sense that it uses numerous abbreviations referring, for example, to the type and flag of the ship or the dates of navigation.

Another commonly included feature is what we refer to as maritime intelligence: brief notes from captains of vessels newly arrived in port, reporting on other ships they encountered during their voyage. These notes provide information on the geographic location of the encounter, the condition of the other vessel, and the approximate date of its departure from the port of origin. This information was of vital importance to the maritime world of the port—shipowners, shipping agents, brokers, and the maritime trade sector in general—who, at the time, had no better means of knowing the situation of their floating enterprises than through these reports..

Le Sémaphore de Marseille can be accessed in its digital version on Gallica, the digital library of the Bibliothèque Nationale de France.