Former US-built tug DPC 95 of the Defense Plant Corporation, and later transferred to the US Army Transportation Service as ST 764. Like many that were stationed in Europe after WW2, she was sold to local towage operators, in this case to France, Fenwick Tyne & Wear Co Ltd, Newcastle as GRANGETOWN. In 1970 sold for continued port towage service to Brodospas, Split as POLARIS.
Conversion to passenger service was in about 2007 for Ivan & Filip Tomic, Bol, Croatia
2016 Moreplovac doo, Croatia
http://www.dalmatiacruising.com/polaris/en/yacht-polaris/53-yacht-polaris

I'd take a guess that her hull dates from 1943 but her upper works are much more recent.

Looks almost like some "ancient yacht" (windows, funnel, the colour scheme, etc)....

Built 1943.... and truly worth to say, she's *beautiful* today!!!