“Shark Bay Through Four Centuries 1616 to 2000. A World Heritage Area” by Hugh Edwards 1999 Scott Four Colour Print , Perth WA
Chapter 7 gives much information about Explorer George Grey
Grey was a dashing young Englishman a lieutenant in Her Majesty’s 83rd Regiment of foot. Born in 1813 he was only 24 years in 1837 when he led an expedition to the Kimberley area. He had unintentionally offended Goverrnor James Stirling using Cape Town not Fremantle for his first sortie to the Kimberley. In addition his skill and knowledge of harsh, unforgiving WA conditions did not yet match his boundless enthusiasm for exploration and adventure. He had come close to being killed on his first Kimberley expedition and had lost most of his dogs, ponies, sheep and gear and was himself speared by natives before being rescued by HMS Beagle.
In 1839 Grey, being an incurable optimist, decided to mount another expedition to Shark Bay – another recipe for disaster. The basic problems were always water & feed for the animals and the fickle nature of the weather and seasonal conditions. Mariners had drawn charts of the WA coast since 1616 when Dirk Hartog had mounted his plate at Cape Inscription but very little was known of the interior north east of about York. The arid region of 200 miles of sand plain north of Yanchep and aggressive Aborigines reputed to be ‘cannibals” had discouraged travellers in that direction. Grey purchased some whale-boats and hired a Yankee whaler to drop him with his people, boats and stores at Shark Bay. He planned to arrive in February, a month when ‘southerlies’ are still howling and roughing up the sea. Whaleboats were built of very light timber with a fine bow entry, double-ended stern and narrow beam. Normally it was used for a quick chase of a whale and carrying only oarsmen and the harpooner, not the loads Grey had in mind in very short seas. Grey proposed to sail (or row) along the coast go ashore at night to camp and explore. This meant running through surf in heavily-loaded whale-boats.
Grey and 11 companions, stores and 3 whale-boats were offloaded on Bernier Island on February 25th 1839.
In the course of the trip he named Gascoyne River (at Carnarvon), sailed and rowed in 56 hours the 120 miles from Steep Point to Gantheaume Bay where the boats were wrecked trying to land in heavy surf at end of March. Now they commenced a nightmare trek on foot back to the Swan River which Grey with Kaiber his faithful aboriginal member of the expedition, reached 3 weeks later, starving, thirsty, exhausted and emaciated. After he was (with difficulty) recognised, rescue parties went north and found the other members of the group some as much as 150 kilometres behind and close to death. One, Frederick Smith, was found dead and buried north of Moore River. Throughout the trek Grey kept a detailed daily journal naming the Gascoyne, Murchison, Hutt, Bowes, Buller, Chapman, Greenough, Irwin, Arrowsmith, and Smith Rivers. The Frederick Smith river was later renamed the Nambung River by surveyor J S Brooking in 1874-75. Grey wrote detailed accounts of his adventures which were well received in England. At 28 years of age in 1840 he was appointed Governor of South Australia, was knighted in 1850 and became Governor of South Africa and twice a Governor of New Zealand.

Just a query?? If George Grey started his trip from Shark Bay heading south towards Perth and was subsequently wrecked in his whaleboats near Kalbari, how on earth did he “discover” the Gascoyne, some 150-200 kms NORTH of Shark Bay?
Grey first landed at Bernier Island and then moved on to the mainland before heading south to Gantheaume Bay where the last boats were wrecked. http://wanowandthen.com/George-Grey.html