Snagboat

A snagboat is a river boat, resembling a barge with superstructure for crew accommodations, and deck-mounted cranes and hoists for removing snags and other obstructions from rivers and other shallow waterways.

During the American Civil War, when much of the naval fighting was done on rivers and their tributaries, numerous snagboats were in operation. USS Benton, for example, was a commercial snagboat quickly converted by the Union Army to a river gunboat when the American Civil War broke out.