diff --git a/APMrover2/RC_Channel.cpp b/APMrover2/RC_Channel.cpp
index ca92e7a281..44d13660ca 100644
--- a/APMrover2/RC_Channel.cpp
+++ b/APMrover2/RC_Channel.cpp
@@ -45,6 +45,10 @@ void RC_Channel_Rover::init_aux_function(const aux_func_t ch_option, const aux_s
     case AUX_FUNC::LOITER:
     case AUX_FUNC::FOLLOW:
     case AUX_FUNC::SAILBOAT_TACK:
+    case AUX_FUNC::MAINSAIL:
+        break;
+    case AUX_FUNC::SAILBOAT_MOTOR_3POS:
+        do_aux_function_sailboat_motor_3pos(ch_flag);
         break;
     default:
         RC_Channel::init_aux_function(ch_option, ch_flag);
@@ -95,6 +99,21 @@ void RC_Channel_Rover::add_waypoint_for_current_loc()
     }
 }
 
+void RC_Channel_Rover::do_aux_function_sailboat_motor_3pos(const aux_switch_pos_t ch_flag)
+{
+    switch(ch_flag) {
+    case HIGH:
+        rover.g2.sailboat.throttle_state = rover.g2.sailboat.Sailboat_Throttle::FORCE_MOTOR;
+        break;
+    case MIDDLE:
+        rover.g2.sailboat.throttle_state = rover.g2.sailboat.Sailboat_Throttle::ASSIST;
+        break;
+    case LOW:
+        rover.g2.sailboat.throttle_state = rover.g2.sailboat.Sailboat_Throttle::NEVER;
+        break;
+    }
+}
+
 void RC_Channel_Rover::do_aux_function(const aux_func_t ch_option, const aux_switch_pos_t ch_flag)
 {
     switch (ch_option) {
@@ -195,6 +214,15 @@ void RC_Channel_Rover::do_aux_function(const aux_func_t ch_option, const aux_swi
         rover.control_mode->handle_tack_request();
         break;
 
+    // sailboat motor state 3pos
+    case AUX_FUNC::SAILBOAT_MOTOR_3POS:
+        do_aux_function_sailboat_motor_3pos(ch_flag);
+        break;
+
+    // mainsail input, nothing to do
+    case AUX_FUNC::MAINSAIL:
+        break;
+
     default:
         RC_Channel::do_aux_function(ch_option, ch_flag);
         break;
diff --git a/APMrover2/RC_Channel.h b/APMrover2/RC_Channel.h
index 96c3b3b165..9b7f4aa9e2 100644
--- a/APMrover2/RC_Channel.h
+++ b/APMrover2/RC_Channel.h
@@ -23,6 +23,8 @@ private:
                                      const aux_switch_pos_t ch_flag);
 
     void add_waypoint_for_current_loc();
+
+    void do_aux_function_sailboat_motor_3pos(const aux_switch_pos_t ch_flag);
 };
 
 class RC_Channels_Rover : public RC_Channels