If you're familiar with Townsville you'd be aware of the volunteer coast guard/marine rescue unit with a couple of quite capable boats, and the water police unit with their boats too. In the event that air resources were needed Rescue 510 (or 512? can't quite remember the exact callsign), a Townsville-based Bell 412 can be deployed as well. Given that Townsville is currently severe CAVOK, barely a cloud in the sky, light wind and negligible swell, its hardly likely to be a high-risk urgent rescue mission, and in the event that it was, there are plenty of appropriate resources available. Taking a guess, a fisherman in his tinny was lost - dropped his one gps overboard - and diverting a kingair without charts or possibly required equipment is hardly likely to help matters. The volunteer coast guard, more power to them, are kept busy retrieving fishermen who run out of fuel, flood their engines, lose their charts, get confused, misread their compasses or otherwise get stuck out there, so they are quite capable of that sort of mission and it happens - not quite daily, but fairly frequently.