decided that the opening between this and Van Diemen's Land is a strait,
this rapidity of tide...will be accounted for." He also wrote: "There is
reason to believe it (i.e., Wilson's Promontory) is the boundary of a
large strait." I do not think these passages are to be taken to mean that
Bass was at all doubtful about there being a strait. On the contrary, the
words "whenever it shall be decided" express his conviction that it would
be so decided; but the diarist recognised that the existence of the
strait had not yet been proved to demonstration. His reluctance to turn
back when he reached Westernport was unquestionably due to the same
cause. The voyage in the whaleboat had not proved the strait. It was
still possible, though not at all probable, that the head of a deep gulf
lay farther westward. The subsequent circumnavigation of Tasmania by Bass
and Flinders proved the strait, as did also Grant's voyage through it
from the west in the Lady Nelson in 1800.

Hunter had no more evidence than that afforded by Bass's discoveries when
he wrote, in his despatch to the Secretary of State: "He found an open
ocean westward, and by the mountainous sea which rolled from that
quarter, and no land discoverable in that direction, we have much reason
to conclude that there is an open strait through." Hunter's "much reason
to conclude" implies no more doubt about the strait than do the words of
Bass, but the phrase does imply a recognition of the want of conclusive
proof, creditable to the restrained judgment of both men. Flinders also
wrote: "There seemed to want no other proof of the existence of a passage
than that of sailing positively through it," which is precisely what he
set himself to do in Bass's company, as soon as he could secure an
opportunity. Still stronger testimony is that of Flinders, when summing
up his account of the discovery: "The south-westerly swell which rolled
in upon the shores of Westernport and its neighbourhood sufficiently
indicated to the penetrating Bass that he was exposed to the southern