During the underwater bridge inspection, a total of 110 no. piles were inspected at Third mainland Bridge and 50 were inspected at Carter Bridge. The scope completed by OCES was to undertake a Level 1 General Underwater Inspection, consisting of confirmation of existing conditions of the piles, detection of visual damage caused by impact, inherent water condition, corrosion and biological attack. The inspection scope included bathymetry datasets collection; to understand the current bed levels to determine current pile embedment depths.