Orkney Image Library

While I can't say what this medallion was for, the design is certainly based on the coat of arms that was used by Stromness Town Council in their seal. The Town Council never recorded the coat of arms and it was only officially recorded in the Public Register of All Arms and Bearings in Scotland when the Community Council petitioned the Lord Lyon King of Arms for a Grant of Arms. The Arms were recorded in Volume 62, folio 111, of the Public Register on 6th March 1985. The date 1817 is the year Stromness was created a Burgh of Barony - 18th February 1817, and the Motto is that used by the Council since 1817.
The Grant of Arms shows a blue background, a gold dragonship under sail, oars in action and flagged, and below this a pair of gold balances. The medallion has been changed to red and blue and the sail white, rather than the recorded colour of gold.
Are there any marks on the back of the pendant to indicate if it is made of gold, sliver, or a base metal? If it is made of brass or some similar metal it might be a swimming medal or something similar. Alternatively, it might have been a bit of tourist tat!!