The animal was spotted sitting on the mud banks in the outer harbour watching the boats come and go and stayed for two days.

t was thought at first it was injured but Premier Marinas staff could find nothing wrong with it and nicknamed it Stuart, after a bald maintenance man who they said looked similar.

Lock keeper Mark Tiernan said, "It showed a lot of interest in watching the boats and seemed to be scared of the water, sitting on the banks waiting for the tide to come in and push it back out into the sea."

It is not the first seal to have turned up at the Harbour, following another two years ago, which came into the Marina itself through the locks.

Mark said at this time of year, particularly at night, lots of wildlife appeared, including foxes, herons and cormorants.

"These seals are not that rare actually," he added.

"They are known as harbour seals and every now and then they come in for a rest and a break, then off they move down the coast again."