Files in this Data Supplement:

• Supplemental file 1 - Fundamental description of methods of data acquisition and processing using VSI (Fig. S1 and S2).
  MS Word document, 22K.
• Supplemental file 2 - Description of the materials and methods used in the study.
  MS Word document, 36K.
• Supplemental file 3 - Quantitative description of how Fig. 1 was interpreted and how the transparent surface of the water and the water/steel interface were defined via numerical methods.
  MS Word document, 22K.
• Supplemental file 4 - Diagram showing how to properly interpret a correlogram (raw interferometric data) so a proper measurement can be obtained for both a transparent surface and its interface (Fig. S3).
  Zipped MS Word document, 203K.
• Supplemental file 5 - Description of the challenges involved in monitoring microbially induced corrosion in vivo using VSI and of the steps that may be employed to overcome these obstacles.
  MS Word document, 34K.