During WWII contributions to the war effort were made by most civilians in both town and country. In industrial areas this was often in munitions factories and in the country the land Girls helped feed the country by working on farms.
From 1943-6 a very much smaller band of ladies made their contribution on the British waterways by crewing narrowboats. I believe the total number of this band of novice boat people was as few as 45.
They were recruited through an advertisement by the Department of War Transport. No boating experience was required but the ladies must be of robust constitution. The applicants received six weeks' training before being put in charge of a motorboat and butty - three ladies to each pair. They then worked 18-20 hours per day carrying all manner of cargo mainly between London and the Midlands. Aircraft parts, coal, sugar, agricultural products all found their way by water. When the gold reserves were moved from the Bank of England to USA for safe keeping they were carried by canal to Liverpool. Unlike the Land Girls, the Inland Waterways Girls did not recieve any additional rations so they supplemented their food with root vegetables taken from fields alongside the canals. Their uniform carried the insignia IW identifying them as Inland Waterways. The resident boaters soon decided IW meant Idle Women.
On the Grand Union canal by Tom O' the Woods near Rowington is this commemoration which has been implemented more successfully.