A monitoring system for offshore subsea and platform structures. The autonomous SIoT (Subsea Internet of Things) devices will be attached to the structure with the capability to operate for more than ten years due to the use of intelligent algorithms that will optimise battery usage. In addition to operating autonomously, the sensors will also be able to communicate with one another. This will allow critical information on fatigue and corrosion to be communicated to deliver field-wide, intelligent monitoring systems.