The rapid development of the offshore wind industry has generated increased interest in marine environments. To obtain environmental data pertinent to the operation of an offshore wind farm, a metrology mast was installed by the Taiwan Power Company (TPC). This study focusses on structural vibration monitoring by the mast. To better understand the dynamics of marine structures under force, it is necessary to measure the interactions between these structures and the surrounding environment. The main purpose of the mast is to enable long-term structural vibration monitoring. The metrology mast, is located six kilometers offshore from Changhua Wang-Gong Fishing Port. The information provided by the mast will have a significant bearing on the design of offshore structures in the future, such as offshore wind turbines. In the present study, we analyze data obtained from the mast, aiming to develop existing knowledge on the dynamics of offshore structures. The content of the article includes: (1) an introduction to the structural vibration monitoring system. (2) The specifications of the measurement equipment. (3) A exhibition of the measurement data.