In Bum's Bay there are several of these posts that have been driven into the sandy bottom, below the low watermark. A number of Little Black Cormorants use them as resting perches, where they can dry off their wings.
Their feathers are not waterproof and as they become waterlogged, the birds tend to swim lower in the water, thus the need to dry off.
Another common name for them is the Little Black Shag, but their official name is Phalacrocorax sulcirostris. Very often seen congregated in large groups, and when flying together form up in a large V shape.
Canon EOS 5D Mark II
Flash: Not Fired
Images Copyright Alan Fear 2007/12