 For sensing below the surface, the class was given one SQS-501 high frequency bottom profiler sonar, one SQS-502 high frequency mortar control sonar, one SQS-503 hull mounted active search sonar and one SQS-504 VDS medium frequency active search sonar.For fire control purposes they were given one Mk 64 GFCS fire control with SPG-48 tracker (GUNAR).The two "Annapolis"-class destroyers were built late enough to incorporate the helicopter hangar retrofitted to the "St. Laurent" class and the "Beartrap" haul-down device.