Subsea actuation sub-system

A subsea actuation sub-system, comprising:

• a valve coupled to a subsea structure, the valve having a valve stem for moving the valve between an open position and a closed position;
• a rotation-to-linear mechanism coupled to the valve stem, the rotation-to-linear mechanism including a shaft with an end for receiving rotational input from a separate retrievable motor actuator;
• a cylindrical bucket with the shaft positioned therein such that the end is positioned within the bucket, the bucket including a cylindrical opening in an axial direction of the bucket and an elongate opening on a side of the bucket, the cylindrical opening being distal from the rotation-to-linear mechanism, the elongate opening elongated in the axial direction;
• and
• a position indicator coupled to the shaft, the position indicator including:
• a first gear coupled to the shaft,
• a second gear in threaded communication with the first gear, the second gear configured to move in the axial direction based on rotation of the first gear and the shaft,
• an element coupled to the second gear, the element extending radially from the second gear,
• a swing pivotably coupled to the bucket, the swing defining a slot that receives the element, the swing including an indicator that is external to the bucket, wherein the swing and the indicator selectively pivot to a position that corresponds to either the open position or the closed position of the valve based on the rotation of the shaft,
• a guide coupled to the bucket, the guide defining a slit that receives the swing, wherein the indicator is located on one side of the slit and the slot on another side of the slit.