There is a sandbar in Sydney Harbour that forms
a boundary to the inner harbour, where the SYSCO wharf is found.
Although harbour ice forms in the inner harbour between the end
of January and the middle of March, this sandbar helps to protect
the inner harbour from drift ice, floating down from the Gulf of
The majority of the vessels that come to Sydney Harbour are ice-class
vessels and are suited to dealing with harbour ice, although when
drift ice does enter the harbour an icebreaker is required. This
has occurred two or three times in the last five years and typically
requires one day to free the harbour.
Drift ice is cleared with either an ice breaker or the Marine Atlantic
passenger ferry which provides service to and from Newfoundland,
and is itself an icebreaker. There have been only one or two instances
in the past few years when the ferry was delayed by a day as the
result of ice in the Harbour. According to the Harbour Master, the
harbour has never been dredged and there is no current need to do
so in the future.