Patent ID: 7598465

Claim:
A switch mechanism usable underwater comprising: an exterior member enclosing an interior region and having first and second holes communicating the interior region to an external region; a pressing operation member providing a watertight seal for the first hole; switch means in the interior region being turned on/off by a movement of the pressing operation member; water pressure detecting means providing a watertight seal for the second hole of the exterior member; and a lever member disposed to be rotatable around a rotation supporting portion disposed in the interior region, for applying a detected force to the pressing operation member when the water pressure detecting means is pressed against the lever member responsive to water pressure applied to the water pressure detecting means, wherein, the detected force applied by the water pressure to the water pressure detecting means is set to be equal to or greater than a resultant force of an external force being received by the pressing operation member from the water pressure as an external pressure, and an internal force being received by the pressing operation member from the lever member as a force in a direction opposite to an applying direction of the external pressure.