Yeah I figured there had to be something I wasn't seeing. Just looking at the numbers I saw, the Gato's looked way superior. I was wondering about maneuverability, which wasn't mentioned. Plus the obvious lack of ability to dive deep compared to German subs. Thanks for all the input.
Also, you know those pics of the Gato in Pearl Harbor you posted? My ship tied up right next to that thing once, and I didn't even check it out