diff --git a/Boat.py b/Boat.py
new file mode 100644
index 0000000..cdafe7c
--- /dev/null
+++ b/Boat.py
@@ -0,0 +1,21 @@
+from Vehicle import Vehicle
+
+class Boat(Vehicle):
+    def __init__(self, brand, model, year, boat_type):
+        super().__init__(brand, model, year)  
+        self.boat_type = boat_type 
+
+    def display_info(self):
+        """Override the parent class method for a Boat."""
+        return f"Boat: {self._brand} {self._model}, Type: {self.boat_type} ({self._year})"
+    
+    def honk(self):
+        """Specific implementation for a boat."""
+        return "Hooo hooo!"
+
+
+if __name__ == "__main__":
+    my_boat = Boat("Jiajian", "242X", 2021, "Speedboat")
+    print(my_boat.display_info())   
+    print(my_boat.honk())           
+    print(my_boat.sail())
\ No newline at end of file
diff --git a/Car.py b/Car.py
index 9741b1f..12ca380 100644
--- a/Car.py
+++ b/Car.py
@@ -12,3 +12,7 @@ def display_info(self):
     def honk(self):
         """Specific implementation for a car."""
         return "Honk honk!"
+        
+    def start_engine(self):
+        """Simulate starting the engine of the car."""
+        return f"{self._brand} {self._model}'s engine has started!"
\ No newline at end of file