Exploration of south-western part of Gulf.
Large inlets discovered.

June 26.

The vessels forming our convoy departed this morning, and soon
disappeared in the western horizon, leaving the Beagle, that seemed
destined to be a solitary roamer, once more alone at anchor under Booby
Island.

On the same evening she was herself pursuing her lonely way towards the
Gulf of Carpentaria, the eastern shore of which we saw on the morning of
the 1st of July. In the afternoon we anchored in 3 1/4 fathoms; the north
end of a very low sandy piece of coast, which we found to be in latitude
16 degrees 13 1/2 minutes South, longitude 9 degrees 10 East of Port
Essington, bearing South 70 degrees East, six miles and a half. From this
place the coast trended South 10 degrees West, and was fringed with
mangroves; a few straggling casuarinas grew near the sandy parts, a
feature which we constantly afterwards found to recur; their tall
broom-like shapes form a remarkable element in the coast scenery of the
Gulf.

SINGULAR TIDAL PHENOMENON.

A fruitless attempt was made to visit the shore, which was fronted for
the distance of a mile by a bank of soft mud. We could therefore gain no
information respecting the interior; but from the numerous fires, it
appeared to be thickly inhabited. It was here that we first observed the
singular phenomenon of the tides ebbing and flowing twelve hours.