Thermally sprayed aluminium (TSA) coatings are widely specified for protecting steel against aqueous corrosion. This includes offshore steel structures and components that are exposed to seawater immersion, tidal and splash zone environments. In this paper, TSA coatings prepared by conventional and newer wire thermal spraying systems are compared. The TSA coatings are characterised in terms of deposition efficiency, coating microstructure, porosity and oxide content, surface roughness and coating bond strength. The corrosion behaviour of the coatings was evaluated using longer-term immersion testing and accelerated electrochemical potentiodynamic corrosion testing in solutions of 3.5wt% NaCl and artificial seawater at ambient temperature. The TSA coating performance was compared in terms of free corrosion potential and corrosion rate estimated from linear polarisation resistance (LPR) measurements. The newer wire spraying systems were shown to produce TSA coatings with improved quality and the effect of this on longer-term corrosion protection is presented. In addition, corrosion behaviour depends on whether the testing is undertaken in NaCl solution or artificial seawater. This is discussed and recommendations given for future testing.