After three weeks of searching for worthwhile targets , '' Sea Owl '' sank her initial victim , a Japanese destroyer escort , with one Mark 27 , which stopped her , and one Mark 18 , from about 1000 yd ( 910 m ) .
After three weeks of searching for worthwhile targets , '' Sea Owl '' sank her initial victim , a Japanese destroyer escort , with one Mark 27 . 
 She followed with a second escort , stopped by a Mark 27 and finished off with one Mark 18 , from about 1000 yd ( 910 m ) .