Abstract: A torpedo apparatus comprises a propulsion module operable to propel the torpedo apparatus through water and a steering module operatively coupled to the propulsion module. The steering module including a plurality of fins which are controllable for controlling a direction of travel of the torpedo apparatus through water. A plurality of head modules are removably and interchangeably attachable to the torpedo apparatus, wherein each of the head modules houses at least one guidance assembly and at least one utility assembly. A power supply module is configured to provide power to the propulsion module, the steering module, and an attached one of the head modules.