Thermally sprayed aluminum (TSA) has been used to protect offshore structures for many years at ambient temperatures. However, the melting point of aluminum, and the limited corrosion rate data indicate that they are likely to perform well in high temperature seawater as they tend to form calcareous deposits. Nonetheless, not much is known regarding the protection mechanism offered by TSA at elevated temperatures. This paper reports micro-scale surface characterization data on damaged TSA-coated carbon steel exposed to boiling synthetic seawater. The corrosion rate, calculated using linear polarization resistance (LPR) technique of TSA was ~10ìm/year. This is very similar to the TSA corrosion rate observed at room temperature. The formation of a calcareous deposit which covers the exposed steel seems to reduce the corrosion rate. Detailed microstructural characterization of the calcareous was also carried out and the kinetic information regarding the rate of formation of calcareous deposits is also presented.