Harbor facilities need regular inspections for damages and
corrosion. The constructions which are not underwater are easily
reachable, but the underwater constructions can only be reached
by divers or when the water is removed. Usually, the underwater
constructions of harbors are inspected for damages, which can
be: collision of vessels with the piers, scouring on walls, piers or
corrosion on walls or sheet pile walls. Different damages are shown
in Figs. 2 and 3.