diff --git a/libraries/AP_DAL/AP_DAL_Compass.cpp b/libraries/AP_DAL/AP_DAL_Compass.cpp
index 3dfa6a0b6f..13bc1c24b5 100644
--- a/libraries/AP_DAL/AP_DAL_Compass.cpp
+++ b/libraries/AP_DAL/AP_DAL_Compass.cpp
@@ -17,6 +17,7 @@ void AP_DAL_Compass::start_frame()
     const auto &compass = AP::compass();
 
     const log_RMGH old = _RMGH;
+    _RMGH.available = compass.available();
     _RMGH.count = compass.get_count();
     _RMGH.auto_declination_enabled = compass.auto_declination_enabled();
     _RMGH.declination = compass.get_declination();
diff --git a/libraries/AP_DAL/AP_DAL_Compass.h b/libraries/AP_DAL/AP_DAL_Compass.h
index b7ee867c95..39bfb66445 100644
--- a/libraries/AP_DAL/AP_DAL_Compass.h
+++ b/libraries/AP_DAL/AP_DAL_Compass.h
@@ -38,6 +38,10 @@ public:
         return _RMGH.declination;
     }
 
+    bool available() const {
+        return _RMGH.available;
+    }
+
     // return the number of enabled sensors
     uint8_t get_num_enabled(void) const { return _RMGH.num_enabled; }
 
diff --git a/libraries/AP_DAL/LogStructure.h b/libraries/AP_DAL/LogStructure.h
index 488e058b26..65b199af63 100644
--- a/libraries/AP_DAL/LogStructure.h
+++ b/libraries/AP_DAL/LogStructure.h
@@ -240,6 +240,7 @@ struct log_RASI {
 // @Description: Replay Data Magnetometer Header
 struct log_RMGH {
     float declination;
+    bool available;
     uint8_t count;
     bool auto_declination_enabled;
     uint8_t num_enabled;
@@ -402,7 +403,7 @@ struct log_RBOH {
     { LOG_RGPJ_MSG, RLOG_SIZE(RGPJ),                                   \
       "RGPJ", "IffffffIiiiffHB", "TS,VX,VY,VZ,SA,Y,YA,YT,Lat,Lon,Alt,HA,VA,HD,I", "--------------#", "---------------" }, \
     { LOG_RMGH_MSG, RLOG_SIZE(RMGH),                                   \
-      "RMGH", "BBfBBBB", "Dec,NumInst,AutoDec,NumEna,LOE,C,FUsable", "-------", "-------" },  \
+      "RMGH", "BBBfBBBB", "Dec,Avail,NumInst,AutoDec,NumEna,LOE,C,FUsable", "--------", "--------" },  \
     { LOG_RMGI_MSG, RLOG_SIZE(RMGI),                                   \
       "RMGI", "IffffffBBBB", "LU,OX,OY,OZ,FX,FY,FZ,UFY,H,HSF,I", "----------#", "-----------" },                                        \
     { LOG_RBCH_MSG, RLOG_SIZE(RBCH),                                   \