This paper investigates on a development of free floating point absorber type of ocean wave energy converter (OWEC) for the gulf of Thailand. The point absorber is designed based on a double mass-spring system. The electric generators are installed in the buoy body and they will slide on a column as harmonic motion. The point absorber is demonstrated in open water channel with wave input. The amplitude and the frequency of the wave are varied, and then the electric power output and the motion of the generators are measured during the wave input. The experiment result presents the relationship between the electricity and stiffness of springs. The peak power output is 1,185 mW that the wave's amplitude is 0.05 m, the frequency is 2 Π rad/s, and the stiffness of the spring is 285 N.m. Thus, the peak power output is approximately 14,000 mW for wave's amplitude and wave's frequency in the gulf of Thailand.