diff --git a/Subsurface/Source/Map/MapEntity.cs b/Subsurface/Source/Map/MapEntity.cs
index 6ec889944..51c2c3a09 100644
--- a/Subsurface/Source/Map/MapEntity.cs
+++ b/Subsurface/Source/Map/MapEntity.cs
@@ -464,7 +464,11 @@ namespace Barotrauma
                     Vector2 moveAmount = Submarine.VectorToWorldGrid(cam.WorldViewCenter - center);
 
                     selectedList = new List<MapEntity>(clones);
-                    selectedList.ForEach(c => c.Move(moveAmount));                    
+                    foreach (MapEntity clone in selectedList)
+                    {
+                        clone.Move(moveAmount);
+                        clone.Submarine = Submarine.MainSub;
+                    }                    
                 }
             }
 
diff --git a/Subsurface/Source/Map/SubmarineBody.cs b/Subsurface/Source/Map/SubmarineBody.cs
index 9b4ab743b..876354fd6 100644
--- a/Subsurface/Source/Map/SubmarineBody.cs
+++ b/Subsurface/Source/Map/SubmarineBody.cs
@@ -160,17 +160,17 @@ namespace Barotrauma
 
         private List<Vector2> GenerateConvexHull()
         {
-            if (!Structure.WallList.Any())
+            List<Structure> subWalls = Structure.WallList.FindAll(wall => wall.Submarine == submarine);
+
+            if (subWalls.Count == 0)
             {
                 return new List<Vector2> { new Vector2(-1.0f, 1.0f), new Vector2(1.0f, 1.0f), new Vector2(0.0f, -1.0f) };
             }
 
             List<Vector2> points = new List<Vector2>();
 
-            foreach (Structure wall in Structure.WallList)
+            foreach (Structure wall in subWalls)
             {
-                if (wall.Submarine != submarine) continue;
-
                 points.Add(new Vector2(wall.Rect.X, wall.Rect.Y));
                 points.Add(new Vector2(wall.Rect.X + wall.Rect.Width, wall.Rect.Y));
                 points.Add(new Vector2(wall.Rect.X, wall.Rect.Y - wall.Rect.Height));
diff --git a/Subsurface/Source/Utils/MathUtils.cs b/Subsurface/Source/Utils/MathUtils.cs
index 0aa6b5760..62f11fab1 100644
--- a/Subsurface/Source/Utils/MathUtils.cs
+++ b/Subsurface/Source/Utils/MathUtils.cs
@@ -381,6 +381,8 @@ namespace Barotrauma
 
         public static List<Vector2> GiftWrap(List<Vector2> points)
         {
+            if (points.Count == 0) return points;
+
             Vector2 leftMost = points[0];
             foreach (Vector2 point in points)
             {