Yes, I agree, this would consume unnecessry power and limit the field of view to around 160 degrees. Normal procedure is to enter a circular holding pattern at approx. 1500ft asl.
If the operation is covert (or in a combat zone) the holding pattern can be as high as 5000ft asl using infrared to detect the surfacing of the boat.
Did you have a bad experience using autohover over water?
YBB