The Horseshoe is located approximately one kilometre to the south east of Blackburn Island. This reef bench is one of the shallower coral communities within the lagoon and is bordered on its western side by an extensive sand hole. This site is a highly sought after snorkelling destination due to the abundance of neon coloured corals dominated by tower corals (Porites sp.) and the calm conditions which often prevail at this location.

The shallower nature of this site also enables the less experienced snorkeler to confidently explore this pristine coral reef. Easily observed amongst the stunning coral outcrops are gardens of sea anemones (Entacmaea quadricolor) each with its own family of McCulloch’s Anemonefish (Amphiprion mccullochi) in attendance. The sand hole adjacent to the coral reef also supports and incredible array of marine life. Cryptic fish species which spend most of their life beneath the sand can sometimes be seen here along with some of the more gregarious species including the Razor Wrasse (Xyrichtys pavo).