From my memory, which is a little old now as I haven't lived in Nobby beach for about 13 years, I would say it would take you over an hour to walk that distance, maybe somewhere betweeen 1.5 hrs and 2 hrs to walk. Why don't you get a bus? All you have to do is cross the hwy, there's a stop near there, and buses heading north all the time. I can't see how it would cost you too much either, it not that long a distance on a bus. Hope that helps.