If the run of water outside the bar should fail, holes may be dug at the edge of the grass, about three feet deep, which will yield a sufficient quantity in two or three days for any vessel that can pass over it.
The flood-tide in the entrance generally ran sixteen hours, and ebbed eight hours.

High water at full and change took place at 10 hours 10 minutes at night; but on the bar the rise and fall was very irregular, and a vessel going in should pay great attention to the depth, if her draught is more than ten feet, for it sometimes rises suddenly two feet.
The spring-tides take place about the third or fourth day after new or full moon.

The variation here is about 7 degrees East.

The situation of Seal Island, from Captain Flinders' observations, is in latitude 35 degrees 4 minutes 55 seconds, and longitude 117 degrees 58 minutes 7 seconds.
A small island was reported in the Sydney Gazette to have been seen in latitude 36 degrees 27 minutes, and longitude 127 degrees 2 minutes East; but as the account says, that Kangaroo Island was seen the same day, which is not less than one hundred and fifty leagues from the above position, it appears too vague to be correct.

(See Horsburgh Supp.