SUNKLANDS OF PORT PHILLIP BAY AND BASS STRAIT 
87 
(II) Shoals of Port Phillip Bay. 
The shoals (Fig. 6) of Port Phillip Bay occupy the whole of 
the southern portion, south of a line from Rosebud, on the Nepean 
Peninsula, to St. Leonards, on the Bellarine Peninsula. This 
Rosebud-St. Leonards line marks the upper portion of the north- 
east face of the Upper Dune Series which slopes into the Inner 
Basin of Port Phillip. 
The shoals at places awash are the South Sand, Middle 
Ground, Great Sand surrounding Mud Islands, West Middle 
Sand, William Sand, and West Sand; nearer the fairway through 
The Heads are the Royal George Shoal and the Victory Shoal. 
Bores (Pari. Pap. 1864-5) have been put down on some of them 
(Fig. 7). The following is a summary of the records of these 
bores, the datum being L.W.M. 
Bores 
1 
ft. in. 
2 
ft. in. 
3 
ft. in. 
4 
ft. in. 
5 
ft. in. 
6 
ft. in. 
7 
ft. in. 
Depth of Water 
Sand 
Sandstone 
13 0 
23 8 
3 4 
7 0 
9 0 
8 3 
8 0 
9 0 
7 0 
5 6 
8 6 
16 6 
4 6 
21 6 
3 6 
12 0 
15 3 
4 9 
15 0 
17 0 
5 0 
An excerpt from the covering letter forwarding this informa- 
tion was as follows: 
The general result of the boring is, that, in every instance a bed of Sand 
varvino’ from 8| to 23* feet thick was passed through terminating in Sandstone 
similar'^to that seen in the cliff at Queenscliff (dune-rock) and into which the 
borings were continued for depths varjdng from 3* to 16|- feet. 
Through the Sands are tideways — South Channel, Pinnace 
Channel, Symonds Channel, Loelia Channel, West Channel, Coles 
Channel and others of minor importance; some of these have 
been dredged and straightened, and it is impossible now to define 
their original courses. They were formed by the scour of the 
tidal streams, not by fluviatile erosion, hence the use of the term 
tideway for them. The Sands are persistently encroaching on 
them, but they are kept clear, partly by the tidal streams and 
pai-tly by dredging. i / a i. 
The following extract is taken from remarks (Aust. Pilot 
Sup., 1926) on the tides and tidal streams of Port Phillip Bay, 
published by the Admiralty: 
Owing to the narrow entrance and the large area of Port Phillip the range of 
the tides within the Heads is small in comparison with that m the entrance, 
water level within the Port is consequently much affected by winds blowing for 
a lone ueriod in one direction and may remain above mean level continuously 
or for some time after southerly gales or below mean level continuously for 
some time after northerly gales. 
