I suspect they know within a few miles where the aircraft is located, based upon the reports centering on the Napali coast. Most have satellite trackers on board these days, I am not sure as to whether Safari does or not.
I flew tours on Kauai for 7 years. I remember one going missing about the same time of day before I left, at first light, every helicopter on the Island got airborne to search, we loaded up the helicopters with "observers", (mostly our office staff---it did not matter which company, people just got on the next helicopter with open seats), it was not till 14:00 that we located the wreckage of that one. Kauai is an inhospitable place.
The fact that there is no beacon going off does not bode well.