The USS Wolverine and USS Sable were converted coal-fired excursion ships with side-wheel propulsion. They operated 7 days a week, weather permitting, but didn't operate in heavy weather. They were capable of 18 knots, and could handle SNJs on days of calm winds, and Corsairs if there was a breeze. They had no overnight accommodation and carried no avgas or weapons. The flight deck overhang would have made them fragile in heavy seas, since the top of the deck was only 27 feet, but they didn't have the range to get that far from a port, and operated fairly close to shore. The aircraft operating from them could have intercepted that German reconnaissance Ju-390 or shot down an errant Japanese fire balloon, but the ships themselves could only ram German or Japanese sailboats operating on Lake Michigan. While it was suspected that Italian frogmen were attempting to attach mines to the ships at port in Chicago, the suspect frogmen were later recovered wearing cement overshoes, and no mines were found.