On September 30 Light decided to explore the inlet himself. There are several reaches or arms of the inlet and Light chose to explore the eastward one. He finds that it has good depth of water in it, despite running eventually into mangroves and is impressed with the possibilities this inlet presents as a safe harbour. It still fails to match the description of the harbour found by Captain Jones, and Light determines to explore further down the coast in search of it.

Captain John Jones had been on the coast in 1833 on a whaling expedition and reported finding a good harbour. He described it as sheltered by an island at its entrance, with a southern passage about a mile wide, with ample fresh water, and some streams running in to it. He also reported on the apparent fertility of the soil around Cape Jervis, and a sheltered bay north of the Cape, and numerous streams on the eastern side of the Gulf. This information was recorded by Charles Napier, a friend of Light's in his book Colonization: particularly in southern Australia... published in 1835.