Acknowledgements
The authors would like to thank the Royal Geographical Society for providing core funding for this project from the Ralph Brown Award. The University of Ulster and British Institute in Eastern Africa provided additional funds and logistical support. We wish to acknowledge the support of Dave Eastwood, Paul Lane, Ciara Herron, Bernie Lafferty, Rory Quinn and Craig Brown. Additional team support was supplied by Donal and Cian Boland, John Joe McGettigan, John O'Raw and Chris McGonigle. Also the staff of the Zanzibar Antiquities Service and the Institute of Marine Sciences (University of Dar es Salaam).