A local position indicating device for a subsea isolation valve that has no other visual signals of its position integrates to the hydraulic actuation system for the isolation valve. Three way valves, connected to an operating control line and a force closed balance line leading to opposed ends of an operating piston, are located by the isolation valve and redirected by a diver or ROV, to locally operate the valve. The balance line has a piston that is displaced with fluid pushed by the operating piston when the isolation valve is opened with hydraulic pressure in the operating control line local connection. The piston connected to the balance line moves an indicator out of its housing for the local indication that the isolation valve is open. Displaced fluid from movement of the piston in the position indicator moves a floating piston to keep seawater away from the indicating piston.