Investigator was built in Glasgow, Scotland, in 1882, and operated by the Adelaide Steamship Company when it was lost. On 24 April 1918 Investigator was on a voyage between Port Pirie to Port Victoria with a cargo of about 200 tons of superphosphate when it grounded on rocks southwest of Wardang Island.
A Marine Board enquiry found that government charts were inaccurate, and cleared the mate, who was on watch, of any blame. The wreck lies on a rocky reef seafloor in about 4m of water. The remains are collapsed and broken down with boilers and tubes and the engine in the centre of site with propeller shaft and iron stern. Some frames and iron plating are collapsed and an unidentified iron object lies just north of boiler.