This paper describes a risk assessment of electric shock based on a experiment which demonstrates a submerged commercial power source. For the experiment a water tank was made and an outlet was installed on an interior wall. After filling the tank with a conductive water solution, the electric potential was measured with the distance, the direction from the power source, the conductivity and the level of the water solution. As a result, the potential distribution due to the outlet energized and exposed to the water solution depends on the distance from the submerged power source, however, the direction from the power source, the conductivity and the level of the water solution seemed to scarcely affected on the electrical shock risk.