Sentence:  After several hours' labour in the deep and fast-flowing waters of the Suir, the <WSD>dragsmen</WSD> struck upon a body that was lying still at the bottom of the river, about two hundred yards from the place where the hat was found, and a short way from the shore. 
Meaning of the word marked with <WSD> tags:  One who drags a body of water in search of something that is submerged.