The marine industry encompasses a vast range of structures that can be challenging to access, and thus highly mobile systems can be useful for efficient structural health monitoring. This research aims to investigate the feasibility of using unmanned aerial vehicles (UAVs) for deploying various non-destructive testing (NDT) methods to inspect steel structures. In addition, we are evaluating piezoelectric patches (PZT) based detection systems that can provide early warnings of corrosion and fatigue cracks. The study analyzes the pitch and catches method using time-of-flight (TOF) to detect cracks and defects, the UAV-based hammer percussion test for frequency response, and the use of an infrared-mounted camera on the drone for NDT purposes. The goal is to identify the best approach for monitoring the health of marine structures.