diff --git a/ArduSub/Sub.h b/ArduSub/Sub.h
index 4defe6f0c1..8c72bfad68 100644
--- a/ArduSub/Sub.h
+++ b/ArduSub/Sub.h
@@ -393,6 +393,7 @@ private:
     int32_t baro_alt;            // barometer altitude in cm above home
     float baro_climbrate;        // barometer climbrate in cm/s
     LowPassFilterVector3f land_accel_ef_filter; // accelerations for land and crash detector tests
+    LowPassFilterVector3f depth_accel_ef_filter; // accelerations for land and crash detector tests
 
     // 3D Location vectors
     // Current location of the Sub (altitude is relative to home)