It may have hit Cahors ( locally pronounced "chaos") reef which is south of Snapper Headland, south of Evans Head. Nothing else in the area to hit offshore around Evans but there are reefs south towards the Clarence.
I lived in Evans Head for 17 years and lots of northbound yachts would track close in to escape the East Australian current which runs south at 1-3 knots offshore in that area. Coming in closer can give you another 1-1.5 knt boat speed which in a cruising yacht might well be 10-20% faster than going out wider.
Some yachts used to get mighty close to Cahors reef in the 80's but these days , with GPS as backup, there's no real excuse for not being aware of the danger in your route planning.
Redhill is a headland at the northern end of Chinamans Beach, well north of Cahors. Several boats have been washed up there in the last 30 years....Cahors reef has claimed a few! My recollection is that at high tide on a calm day these is no visible sign of the reef although there is visible white water with any sort of swell.
Thankfully, on this occasion all 6 crew were saved by the Evans Head Coast Guard skippered by Tony McNally, an ex-prawn trawler skipper who would know all the local currents and dangers like the back of his hand.

Here's some info on the SS Cahors which was the vessel that "discovered" the reef the hard way!

CAHORS PASSENGER SHIP 1883-1885CAHORS PASSENGER SHIP 1883-1885
<div>
<div class="floatRight">ENNLFRDEESIT??????PT??