Henrietta Rocks - Rottnest Island snorkelling

Henrietta Rocks, below Lookout Hill on the island's south-east corner, is known for the wreck of the Shark, a Fremantle Harbour Trust hopper barge. On 10 February 1939 she was being towed out to be scuttled off Cape Vlaming when the tow line fouled the launch's propeller in a heavy swell. The barge was cut adrift, washed onto the reef in Porpoise Bay, and has stayed there ever since.

The rusting steel hull lies in shallow water a few tens of metres from shore, with parts still showing above the surface, and it is one of only two Rottnest wrecks that the official heritage trail recommends as a snorkel from the shore. Reef fish such as western buffalo bream, scalyfin and damselfish gather around it.

Around the wreck, limestone reef with coral is ringed by seagrass, giving a varied mix of habitat in a small area. It is at its best on calm, flat days.

• Experience level: Easy
• Depth: 1-4 m
• Access: Island Explorer Stop 3 (Henrietta Rocks); about 10 minutes by bike, or under 30 minutes on foot, from Thomson Bay. The Shark wreck lies a few tens of metres off the beach, with parts showing above the water. No facilities and no accessible beach entry (RIA). Calm seas only: the beach is open to ocean swell, which clouds the water and surges around the wreck's sharp, rusting edges.
• Historic Shipwreck (1939)
• Wreck Above Water
• Shore Snorkel Wreck
• Reef & Seagrass
• Shallow Waters

See live conditions for every Rottnest Island snorkelling spot