In early 1844 , Halkett successfully tested a prototype boat-cloak on the River Thames , paddling it 15 kilometres ( 9.3 mi ) without taking on any water , despite , in his words , being `` met by-passed by-and almost run down by-various Metropolitan Steamers plying to and fro in their several vocations , and causing no little commotion in the troubled waters of the River '' .
In early 1844 , Halkett tested the first boat-cloak on the River Thames .