Merchant tonnage to be sure. However, they were constantly sent out after warships via Ultra intercepts. Of course, they were also used for special missions; pilot rescue, evacuations, guerilla insertions, etc.
Early on, the US command sent its boats willy nilly with poor results. Later, after they started concentrating on merchant shipping (tankers in particular), results were much better. Also, when they started prosecuting targets in strategic bottlenecks like the Luzon straights, results were profitable.
__________________
"You know, you might get surrounded." "We're paratroopers, Lieutenant. We're supposed to be surrounded." --Band of Brothers
|