We used UAV（Unmanned Aerial Vehicle） for the part of the investigation for the operation and maintenance at the fishing port facilities. The decrepit degree diagnosis at the facilities which used UAV can implement work correctly and safely. The settlement of the precast concrete armor unit and crack width on the concrete structure were measured using UAV. The extraordinary acceptance standard of the sinking of the precast concrete armor unit is defined as being 'the height which exceeds a block 1 layer'. The measurement accuracy which used UAV was judged enough. The threshold of the crack on the breakwater was 10 mm wide but could measure a crack well of the degree from the image which was photographed from the 20 m height.
