The Marie-Séraphique, a slave-trading ship from Nantes in the 18th century

The Marie-Séraphique had a keel length of 63 feet (20.41m hull length) and a beam length of 23 feet (7.45m width), a draught of 11 feet (3.56m), and a carrying capacity of 150 tons. It transported  between 302 and 361 African captives over the course of its four voyages, and had a crew of between 38 and 41 men. The Marie-Séraphique is an example of an average-sized trading vessel, although it is difficult to determine a standard. While there was a tendency to increase the size of vessels throughout the 18th century, with the use of large carriers of 400, 500 or even more tons, modest-sized ships of less than 100 tons were still commonplace throughout the period.

As shown in the two drawings above, the “Section of the ship” (ill. 2) and the “Steerage” (ill. 1), the search for profit led the organizers of the expeditions to optimize space in order to cram in as many people as possible. The volume of the hold was divided according to two principles: the separation between the zones containing the reserves of water, food, and equipment, and those housing the captives. There was also a separation between the men, always more numerous, placed in the centre and at the front of the ship, and the women, pregnant or not, accompanied by children, confined to the back. The usable surface area was designed to accommodate four individuals per square metre, who were crammed together,  naked, and chained in pairs to further reduce their mobility.

In theory, the captives were only grouped together in steerage at night or during bad weather. To limit the physiological and psychological risks, it was essential to allow the captives out into the open air: this was normally the case from 9am to 5pm, between the two mealtimes. In addition to cleaning operations in steerage, which were entrusted to captives supervised by sailors, the prisoners alternated manual work sessions with physical exercises that sometimes went as far as dancing, according to the recommendations in the slave-trading manuals or the instructions given to the captains by the shipowners. However, when the captives were kept in steerage, their health degenerated at a rapid and dangerous rate. While the Marie-Séraphique was not affected by epidemics or revolts; the mortality rate of the captives, from 2% to 6% of the workforce depending on the campaign, was lower than the average established at 15% for transatlantic trade.

It is also important to insist on the duration of the crossing of the Atlantic Ocean. The “middle passage” generally lasted around two months, a time frame that was typical throughout the 18th century. If the duration naturally depended on weather conditions, it also depended on the African point of departure. From Senegal, a crossing of three to four weeks was not unusual. From the coast of Angola, as in the case of the Marie-Séraphique, which traded in Loango, it took 40 to 60 days. This crossing, of uncertain duration, required sufficient fresh water supplies to ensure the survival of the crew and captives. For the Marie-Séraphique, 335 barrels of water are mentioned in the ship’s log, that is to say approximately 62,500 litres, for the purposes of drinking, cooking, and washing. We can therefore understand the importance of the so-called “refreshment stopovers” that allowed traders to show off the captives in a more presentable light in order to sell them to the colonists. This type of sale can be seen in the drawing titled Vue de Cap-Francais (ill. 2), the main port of the colony of Saint-Domingue, located near lucrative sugar plantations. Transactions took place onboard the ship where the captives were sold in lots. Payment for the captives was made either in colonial goods or in money, and payments were often spread over several years.