The expansion of subsea industrial activities has increased the demand for reliable robotic systems capable of performing inspection and intervention tasks in deep-water environments. In particular, the integration of high-performance vision systems into autonomous and remotely operated underwater platforms remains a critical engineering challenge due to severe hydrostatic pressure, hydrodynamic loading, and space constraints imposed by robotic manipulators. This work presents the conceptual development, mechanical design, and structural validation of a compact underwater vision module intended for deployment on a robotic arm operating in offshore environments. A systematic engineering design methodology is adopted, beginning with requirement definition and concept generation, followed by a comparative evaluation of alternative configurations using a structured materials and design selection framework. The selected concept is subsequently refined through detailed mechanical design, including material specification, geometric optimization, and sealing strategy definition. Structural integrity is assessed through numerical simulations based on the finite element method, accounting for external pressure loads representative of deep-sea operation. In addition, fluid–structure interaction effects are indirectly evaluated through dynamic analyses aimed at minimizing hydrodynamic resistance. The numerical results confirm that the proposed housing maintains structural safety at operational depths up to 300 m, while achieving a substantial reduction in hydrodynamic loading relative to a previous design generation. The developed solution demonstrates improved robustness, compactness, and hydrodynamic efficiency, supporting its suitability for integration into underwater robotic manipulation systems.