The Bottom-mounted ocean-observation platforms installed on the seabed have been used for marine environment analysis. The role of the observing platform is to collect precise observation data without human assistance. However, their working environment is very harsh so the typical device could not afford to provide easy accessibility during their working period. Existing bottom-mounted ocean-observation platforms have been difficult to collect continuous observation data. Therefore, this paper suggests a new ocean-observation platform for precise measurement of the marine environment. Suggested platform uses a PID control method to be applied for error compensation of each axis of gimbal. To verify the system performance, the experiment was carried out in the air with the external force applied to this system.