The explorer Captain Charles Sturt describes in his journal the water as he approached Lake Alexandrina, at Pomanda Point in 1830. Sturt writes:
"Thus far, the waters of the lake had continued sweet; but on filling a can when we were abreast of this point, it was found that they were quite unpalatable, to say the least of them. The transition from fresh to salt water was almost immediate, and it was fortunate we made the discovery in sufficient time to prevent our losing ground. But, as it was, we filled our casks, and stood on, without for a moment altering our course."
For more historical information about the Lower Lakes early exploration see The Case for Seawater