MASTERMAN was built by Cochrane's in 1923 as their YN785 for United Towing.
She became WATER COCK for Gamecock Steam Towing in 1925.
In later life she was seen as WATERCOCK, but I'm not sure whether her registered name was one word or two.
She lasted till 1966 when she was scrapped in Belgium.

This is the same WATERCOCK but in an earlier form with some side stanchions.