The robotic arm structure and control algorithm are designed for a purpose, to pick and place an object task at underwater which is attached to a ROV (Remotely Operated Underwater Vehicle). It is controlled by an innovated gesture control system, Leap Motion controller. The arm structure of pick and place is controlled by Arduino as microcontroller to control the angles and displacements of the servomotor precisely. The detection of position and orientation of the fingers and hands processed by develop control algorithm in Javascript language and sent to the Arduino. Meanwhile, a detailed 3D drawing is drawn precisely by using SolidWorks for the fabrication. After the platform is completed, kinematic and inverse kinematic equations and calculations are programed into JavaScript language for the control algorithm. Lastly, the hardware and software combined all together. With developed control algorithm, the robotic arm mimics human’s fingers and arm movements which more user friendly interface especially underwater scavenging and salvaging. Since it designed for underwater, the accuracy and precision are crucial for robotic arms, it undergo several experiments and tests for investigate reliability performance of developed robotic arm.