The construction of coastal protection embankments is one of the key strategies for mitigating subsidence-induced flooding in coastal areas. This study analyzes the cycle time of spun pile driving work using the inner bore method in the NCICD coastal protection embankment project. The inner boring method was chosen for its advantages in reducing noise, vibration, and environmental impact. However, its application in water environments presents challenges, such as the stability of work pontoons and weather factors. This study employs field observations and descriptive statistical analysis to evaluate cycle time and piling productivity. The results indicate that the average cycle time for piling work is 2.34 h per pile, with an average productivity of 0.51 piles per hour. Factors such as environmental conditions and work methods significantly influence deviations in cycle time and actual productivity compared to the plan. With more optimal time management, work productivity can be improved, allowing the project to be completed more efficiently. This study provides a foundation for planning and scheduling similar projects in the future.