The South Shetland Islands were discovered in 1819. Almost immediately the fur seal population was intensively exploited and this lasted through the early years of the 1820s, by which time seal numbers had been so depleted that sealing became uneconomic. Sealing was revived for both fur seals and Elephant seals at several periods later in the century. Sealers were put ashore in gangs and built makeshift shelters in which to live. Many of these have been identified on the South Shetlands, and a number have been excavated, though few with archaeological method. Fifty known sites are identified. The paper outlines the survey and excavation of two sites on Rugged Island by archaeologists from Australia and from the Chilean National Natural History Museum. One site relates to the sealing era of the 1820s, while the second may be associated with a marooned sealing gang in the 1870s. The nature of the occupation sites on the South Shetlands is analysed in relation to the social and operational context of the merchant navies of Britain and the USA in the nineteenth century. This is seen as a more directly relevant context for assessing physical evidence than is the application of theories of global capitalist systems.