diff --git a/CMakeLists.txt b/CMakeLists.txt
index a1418ef..8df4331 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,9 +29,11 @@ set(common_msg
   # internal
   "msg/HelperAISShip.msg"
   "msg/HelperBattery.msg"
+  "msg/HelperDimension.msg"
   "msg/HelperGenericSensor.msg"
   "msg/HelperHeading.msg"
   "msg/HelperLatLon.msg"
+  "msg/HelperROT.msg"
   "msg/HelperSpeed.msg"
 )
 
diff --git a/README.md b/README.md
index 958ae4b..f595d8b 100644
--- a/README.md
+++ b/README.md
@@ -35,9 +35,11 @@ ROS messages and services used across many ROS packages in the project.
 | ------------------- | ---------------------------------- |
 | HelperAISShip       | AISShips                           |
 | HelperBattery       | Batteries                          |
+| HelperDimension     | HelperAISShip                      |
 | HelperGenericSensor | GenericSensors                     |
 | HelperHeading       | DesiredHeading, GPS, HelperAISShip |
-| HelperLatLon        | Path, GPS, HelperAISShip           |
+| HelperLatLon        | GPS, HelperAISShip, Path           |
+| HelperROT           | HelperAISShip                      |
 | HelperSpeed         | GPS, HelperAISShip, WindSensor     |
 
 ## Boat Simulator Interfaces
diff --git a/msg/HelperAISShip.msg b/msg/HelperAISShip.msg
index e1212b6..9091d4f 100644
--- a/msg/HelperAISShip.msg
+++ b/msg/HelperAISShip.msg
@@ -1,5 +1,10 @@
-# AIS identifier
+# AIS identifier (MMSI)
 int32 id
 HelperLatLon lat_lon
-HelperSpeed speed
-HelperHeading heading
+# The ship's course over ground
+HelperHeading   cog
+# The ship's speed over ground
+HelperSpeed   sog
+HelperROT   rot
+HelperDimension width
+HelperDimension length
diff --git a/msg/HelperDimension.msg b/msg/HelperDimension.msg
new file mode 100644
index 0000000..4beaa0d
--- /dev/null
+++ b/msg/HelperDimension.msg
@@ -0,0 +1,2 @@
+# Unit: meters
+float32 dimension
diff --git a/msg/HelperROT.msg b/msg/HelperROT.msg
new file mode 100644
index 0000000..7b6f6ca
--- /dev/null
+++ b/msg/HelperROT.msg
@@ -0,0 +1,3 @@
+# Rate of turn of the ship, negative for CCW turning and positive for CW turning.
+# Unit: degrees/hour
+float32 rot