[TorpX]

Originally Posted by YonMaruIchi

Off topic but I'm sure the Momo's age had something to do with it. ...
According to wiki by WWII that ship was the only ship of its class to actually still be used in WWII and wasn't even classed as a destroyer, but an auxiliary escort, and was barely even ocean-going, just an unnamed coastal patrol boat.

The IJN wasn't going to dedicate their latest and greatest DD's to ASW. They would be screening CV's and BB's and looking for trouble in fleet actions. The Momi patrol boats were second-class, and therefore all the more likely to be deployed for the job of chasing after USN subs.

In fact the RN and USN used a lot of second-class vessels for ASW duties, too.