 On 12 September, she conducted a 4-hour attack on a Japanese submarine off Guadalcanal, and although debris and an oil slick rose to the surface, she was not credited with a kill.Undaunted, "Griswold" struck again 3 months later and this time recorded a kill.At 2200 on the night of 23 December, patrolling off Lunga Point, Guadalcanal, she was dispatched to investigate a periscope sighting.