diff --git a/ArduSub/Sub.h b/ArduSub/Sub.h
index ede84d300d..0b96004414 100644
--- a/ArduSub/Sub.h
+++ b/ArduSub/Sub.h
@@ -174,11 +174,6 @@ private:
     AP_RPM rpm_sensor;
 #endif
 
-    // Inertial Navigation EKF
-    NavEKF2 EKF2{&ahrs, rangefinder};
-    NavEKF3 EKF3{&ahrs, rangefinder};
-    AP_AHRS_NavEKF ahrs{EKF2, EKF3, AP_AHRS_NavEKF::FLAG_ALWAYS_USE_EKF};
-
 #if CONFIG_HAL_BOARD == HAL_BOARD_SITL
     SITL::SITL sitl;
 #endif