British profits were made from exporting manufactured goods to Africa and importing slave products such as sugar. Ports such as Glasgow, Bristol and Liverpool prospered as a result of the slave trade.
The slave trade contributed to the growth of the both the Royal Navy and the United Kingdom's merchant navy.
The Royal Navy grew during the period of conflict for control of the colonies. Once Britain had grown to dominate the Caribbean, the Navy was still needed to protect these colonies and British shipping.
The growth of trade in slaves, in plantation crops and in exports to American and Caribbean colonies led to a growth in shipping.
Overseas trade was carried out within the rules of the Navigation Acts. These stated that all commodity trade should take place in British ships, manned by British seamen, trading between British ports and those within the Empire.
Additional laws were introduced that gave British shipping companies an advantage over foreign competitors:
A network of trading links between Europe, Africa and the Americas developed. The most well-known part was the triangular trade route:
The slave trade was an important training ground for British seamen, providing experienced crews for the merchant marine and the Royal Navy.
However, the high death rate, particularly from disease, meant that the slave trade could also be considered a graveyard for seamen.