Isthmus Bay a body of water in South Eastern Tasmania. It is a bay of Bruny Island
History
Isthmus Bay was discovered by M. de Cretin, of D'Entrecasteaux's expedition, on 1 May 1792. On 21 May M. de St. Aignon, while searching for an exit from the channel, beached his boat in Isthmus bay, and (minus his clothing) waded ashore, his gun in one hand and his compass in the other. On 13 February 1793, M. de Well and the famous geographer M. Beaupre, returned to the bay. The French found abundance of fish in the bay, it being recorded that one fish caught weighed 100lb., while another weighed 260lb. The French discoverers gave the name of Isthmus Bay to the whole of the water now included in the bay of that name, as well as Great Bay. To the isthmus they gave the name of St. Aignon.