Patent ID: 7633027

Claim:
A switch mechanism usable underwater comprising: an exterior member; watertight switch means provided along the exterior member to maintain water-tightness with respect to water pressures not greater than a predetermined water pressure; an operation member which includes an operation portion and a pressing portion for pressing the watertight switch means, a rotational axis portion arranged near one end of the operation member, the pressing portion being positioned between the operation portion and the rotational axis portion; and biasing means which causes the operation member to rotate around the rotational axis portion by generating a biasing force that is greater than an amount of force generated at the watertight switch means when said predetermined water pressure is applied to the watertight switch means, the biasing force being applied in a direction to move the operation portion of the operation member away from the exterior member; and a positioning member which limits movement of the operation member around the rotational axis portion with respect to the exterior member against the biasing force of the biasing means.