The John Robb was built in Port Adelaide in 1879 and sank during a storm around 1910 and is in the outer shipping channel to Outer Harbour. The wreck is now nearly completely broken up with only the bow section recognisable sticking out of the sand pointing west. The wreck is extremely difficult to locate as land marks are almost impossible to find and a reliable GPS bearing is needed. Marine life around the wreck varies from prolific to almost barren depending on the day. Visibility is generally fairly good due to the distance offshore, but it is subject to tidal currents which can be strong.