Below the lighthouse at Airey’s Inlet is the Eagle Rock Marine Sanctuary (17.9 hectares) which extends from the high-water mark around the base of Split Point between Castle Rock and Sentinel Rock in the township of Aireys Inlet. It extends offshore for about 300 metres and includes the 20-metre-high Eagle Rock a tall volcanic stack capped by limestone, and Table Rock, which has been levelled by the incessant waves.

The main habitats protected by the sanctuary include intertidal and subtidal soft sediment, intertidal and subtidal reefs, and the water column. The intertidal sandstone platform and basalt boulders are home to 25 species of algae.

The shore rock platforms are covered in swathes of Neptune’s Necklace, a brown seaweed that looks like strings of beads.  Marine life abounds in the deeper rock pools, with animals including octopuses, decorator crabs, chiton, and schools of tiny silver fish.

The offshore rocks are fringed by swirling Bull Kelp and Crayweed, which thrive in the breaking waves.  On calm days, however, a snorkel around the rocks can be very rewarding. Colourful sea-tulips and encrusting sponges grow on the rocks.  

Twenty-five species of fish are found in the sanctuary including the Blue-throated Wrasse, Rosy Wrasse and Sea Sweep, while harmless Port Jackson Sharks, Sparsely-spotted Stingarees, and Rusty Catsharks are often seen particularly around reef ledges.