Bode plots of (a, c) impedance magnitude and (b, d) phase angle as a function of frequency recorded in artificial seawater for (a, b) Al-Si9-Cu3 and (c, d) Al-Si7-Mg0.3 samples before immersion in the Adriatic Sea and after 1, 3, and 8 months immersion. Before electrochemical measurements, the samples were sonicated to remove the biofilm formed during immersion. For the samples immersed for 8 months, it was difficult to find an area free of biofouling sufficient to perform three replicates; blue circles presented these curves.