Helicopter hovering is a very difficult task. The helicopter has an Automatic Flight Control System(AFCS) or the autopilot to keep it moving at a certain speed and at a certain height. The pilot can then take a break from the flight. But let me tell you a little something about hovering.
There are three controls in a basic helicopter:
1) Collective stick (main rotor) :- This is responsible for controlling the amount of lift generated.

2) Cyclic stick (main rotor):- This is used to move forward, backward, left or right.

3) Rudder pedals (tail rotor) :- This is used to change the direction of the helicopter or rotate.

Let's analyze this activity -
Step 1: To hover, the pilot has to first reach a certain height and maintain it by using the collective stick.
Step 2: To prevent any motion in the forward or consequent directions he has to use the cyclic to compensate such motion.
Step 3: He has to prevent the helicopter from rotating by using the pedals.
Meaning he has to adjust all the three controls carefully with tremendous skill to keep the helicopter in a stable hovering position. Also he has to constantly monitor the landscape or any fixed point outside his cockpit to make sure that the chopper is stable.
This requires years of training and a pilot's ingenuity which I believe is very very difficult to mimic by a machine. Search and Rescue by Helicopter is never a one man job. This endangers the safety of the pilot and also the chopper.