EntranceChannel
ENTRANCE CHANNEL
The Entrance Channel for the Port of Townsville is 302 ft (92 m) wide, with a depth of 38.4 ft (11.7 m) below lowest astronomical tide (LAT). The channel begins approximately 6.4 nmi north-northeast of the harbor entrance (Figure XI-18). The first section of the channel is named Sea Channel. Its seaward end is approximately 0.75 nmi east of Magnetic Island. Sea Channel is oriented 201°30'/021°30' for a distance of 2.9 nmi, where it then becomes Platypus Channel. Platypus Channel changes direction by 10 degrees and continues on a bearing of 211°30'/031°30' for another 3.5 nmi to the Port of Townsville. While depths in the channel are maintained at 38.4 ft (11.7 m), depths bordering the channel on both sides gradually shoal from its seaward end, becoming less than 16.4 ft (5 m) for the last mile of its approach to the Port. A cautionary note on DMA Chart 74234, Townsville Harbor, states: "The depths in Platypus Channel, Townsville Harbor and Ross River Channel are subject to frequent change."
Source: http://www.nrlmry.navy.mil/port_studies/thh-nc/australi/townsvil/text/sect3.htm
