The sandstone reefs that are within the Marine Sanctuary are known as Little Henty Reefs and are about 80 metres offshore from the beach. Both reefs are clearly visible at low tide and at high tide the tops are still visible.

Due to the location and configuration of these reefs, a wide variety of microhabitats are present in a very small area. The remote location of these islands has ensured that they are packed with sea-life. A rich intertidal reef lies along the top of the sandstone islands.

Things to do

The reef offshore from Marengo is a great destination for snorkellers when conditions are suitable. A short swim from the beach, the reef supports extensive beds of bull kelp which in turn host a wide diversity of smaller red and brown algae and a wealth of invertebrate life.

The shelter provided on the inside of the reef makes conditions suitable even for beginner snorkellers on a good day. Outside the protection of the reef the exposure to ocean swell creates a more dynamic environment better suited to experienced snorkellers and divers.

The sanctuary is only a short drive along the Great Ocean Road from Apollo Bay, where there are full services, including boat launching facilities and a Visitor Information Centre.

Local directions

The Sanctuary is located near Apollo Bay close to the shore at Marengo.

Facilities

Activities

Additional business information

Geological, Hydrological and Landform Features
Henty and Little Henty Islands have been flattened over thousands of years by the waves and now barely show above the surface. The topmost parts of the reefs are exposed at low tide and still visible at high tide. The substrate is relatively smooth cretaceous sandstone surrounded by sand. The reef edges consist of crevices and ledges contributing to habitat diversity. Average depth around the reefs is 5 metres with a depth range to approximately 16 metres. The northern side of the reef is protected from prevailing swells. Strong currents flow in the channel between the reefs. Because of their configuration, the reefs provide a wide variety of microhabitats in a small area. It is the only offshore reef sheltered from prevailing swell along the Great Ocean Road between Anglesea and Peterborough.

Precautions
For your own safety, only undertake activities appropriate to your skills and abilities. Take all necessary precautions, be aware of changing conditions, and watch for potential hazards, such as rips. A number of Victorian marine animals are potentially harmful if not treated with respect and care, so ensure that you familiarise yourself with these species. Sunburn and hypothermia are also potentially harmful but easily avoided. SCUBA diving is a potentially high-risk activity and should only be undertaken by appropriately qualified people that have completed recognised training and certification. Victoria?s cool water environments can be extremely challenging to those used to diving in warmer waters so ensure that local knowledge is sought before undertaking a dive in a new location. Dive charter operators can provide some of the best advice on diving in Victoria.