Developed and integrated an altitude control mode for the BlueROV2 within the PX4/PX4-Autopilot repository, enabling manual height adjustments while maintaining roll and pitch stability for underwater robotics applications. The work involved refactoring the height controller logic into a dedicated module, introducing parameterized height control, and refining thrust calculations to improve altitude accuracy. Additional enhancements included state observation for safer mode transitions and code hygiene improvements such as submodule updates and formatting cleanups. Leveraging expertise in control systems, embedded systems, and robotics, the developer utilized C++ to deliver a modular, maintainable solution that enhances operational reliability for BlueROV2 deployments.