The National Archives Catalog has a great collection of World War I era photos online. 60,000 plus photos in a collection called the "American Unofficial Collection of World War I Photographs , 1917-1918." It has lots of photos of ships built or refurbished on the Great Lakes for the war effort. Here's a small sampling
Lake Ormok
Lake Janet
Northern Wave One of at least four older ships from the Great Lakes Transit Corp. that were cut into 2 pieces and taken to the ocean for use during the war.
Shipbuilding and Ice Cutting, Duluth
Lake and Ocean Navigation Co, Sturgeon Bay
E.C. Pope cut in two. Looks like a new pilot house structure was built mid-ship for ocean service.