On the 29th of April 1830, Barker and his party of explorers reached the mouth of the Murray. Barker was the only person who could swim, so strapped a compass on his head and swam the narrow channel on his own. He walked over a sandhill on Hindmarsh Island where his men heard a sharp cry and Barker was never seen again. The exploration party waited for Barker to come back, but there was no sign of him. They then decided they needed to get help so headed back to the ship which was anchored off Rapid Bay and sailed to Kangaroo Island to get help from the seal hunters who lived there