The trading companies and private merchants used two routes from Denmark to the colony in the West Indies: the triangular route, with a stop in Guinea to pick up enslaved laborers, and the direct route.
The triangular trade
The triangular route went between Denmark, Guinea in Africa and the West Indies. A ship sailed first to Guinea to pick up enslaved laborers. Then it sailed to the West Indian islands, where the enslaved laborers were delivered and the ship was loaded with raw sugar, cotton, coffee, rum and other goods. Finally it sailed back to Denmark. It typically took eighteen months – often it took six months in Guinea to get enough enslaved laborers. In the first few decades after 1672, about half of the ships sailed the triangular route, but from the 1730s the triangular trade ebbed away. From 1803, transatlantic trading in enslaved laborers under a Danish flag was completely prohibited, although the slave trade did continue illegally to a limited extent.
The direct route from Denmark to the West Indies
From the 1730s onward, the great majority of ships sailed directly between Denmark and the Danish colony in the West Indies. During the flourishing trade period of 1755-1807, this accounted for 96 percent of the ships – only 4 percent sailed the triangular route. The sailing ships usually departed from a Danish port in the spring or the fall. The route went through the English Channel. Wine and fresh supplies were often purchased at Madeira before continuing southward and catching the northeasterly trade winds, favorable winds that could send the ship westward to the West Indies. In the West Indies, the cargo was unloaded and a return cargo was loaded. Then course was set northward past Bermuda and on across the Atlantic in a curve with the Gulf Stream toward Denmark.
The sailing time for a direct voyage was typically nine months: three months for the outward journey, three months in a West Indian port and three months for the homeward journey. This meant that a sailing ship generally could only accomplish one expedition a year. The great majority of the ships had Copenhagen as their home port. But maritime cities such as Altona in Holstein, Flensborg in Schleswig and Bergen in Norway frequently participated in trade and shipping in the West Indies.