diff --git a/ArduSub/Parameters.cpp b/ArduSub/Parameters.cpp
index 978f4bef50..05b42f125a 100644
--- a/ArduSub/Parameters.cpp
+++ b/ArduSub/Parameters.cpp
@@ -468,7 +468,7 @@ const AP_Param::Info Sub::var_info[] = {
     // @Values: 0:Disabled, 1:Enabled, -3:Skip Baro, -5:Skip Compass, -9:Skip GPS, -17:Skip INS, -33:Skip Params/Rangefinder, -65:Skip RC, 127:Skip Voltage
     // @Bitmask: 0:All,1:Baro,2:Compass,3:GPS,4:INS,5:Parameters+Rangefinder,6:RC,7:Voltage
     // @User: Standard
-    GSCALAR(arming_check, "ARMING_CHECK",           ARMING_CHECK_ALL),
+    GSCALAR(arming_check, "ARMING_CHECK",           -66),
 
     // @Param: DISARM_DELAY
     // @DisplayName: Disarm delay
diff --git a/ArduSub/config.h b/ArduSub/config.h
index ccb73c7cbd..0ce335f14b 100644
--- a/ArduSub/config.h
+++ b/ArduSub/config.h
@@ -514,7 +514,7 @@
 #endif
 
 #ifndef THR_MIN_DEFAULT
- # define THR_MIN_DEFAULT       130             // minimum throttle sent to the motors when armed and pilot throttle above zero
+ # define THR_MIN_DEFAULT       0             // minimum throttle sent to the motors when armed and pilot throttle above zero
 #endif
 #define THR_MAX                 1000            // maximum throttle input and output sent to the motors
 
@@ -550,10 +550,10 @@
 
 // default maximum vertical velocity and acceleration the pilot may request
 #ifndef PILOT_VELZ_MAX
- # define PILOT_VELZ_MAX    250     // maximum vertical velocity in cm/s
+ # define PILOT_VELZ_MAX    50     // maximum vertical velocity in cm/s
 #endif
 #ifndef PILOT_ACCEL_Z_DEFAULT
- # define PILOT_ACCEL_Z_DEFAULT 250 // vertical acceleration in cm/s/s while altitude is under pilot control
+ # define PILOT_ACCEL_Z_DEFAULT 50 // vertical acceleration in cm/s/s while altitude is under pilot control
 #endif
 
 // max distance in cm above or below current location that will be used for the alt target when transitioning to alt-hold mode