Sound recordings in the vicinity of the unit were made over a period of 2 days, at various states of tide, with the unit running and idle. The sound recordings were made using a high fidelity digital system, and all data stored for post processing. The recorded data includes time and position stamping. The sound data has been post processed to provide intensity vs range plots, with Power Spectral Densities and weighted measurements by M, and dBht factors appropriate to the local mammalian fauna. The report describes field measurement methods, data processing and presentation, of underwater sound attributed to the operation of the SeaGen electrical power generator.