This project involves the mechanical properties and microstructural evaluation of AA6082 aluminum alloy, which is fabricated using underwater friction stir additive manufacturing (FSAM). The focus is on examining the influence of the underwater environment on the material’s strength, toughness, and overall structural integrity. Key evaluation metrics include tensile strength, hardness, and the examiNotion of the alloy’s microstructure for any potential defects. The underwater friction stir additive process aims to improve the manufacturing quality by minimizing heat-affected zones and enhancing material bonding, which is critical for applications in harsh underwater conditions, such as in marine structures or submarine components.