diff --git a/Liner/Liner/DrawingObjectShip.cs b/Liner/Liner/DrawingObjectShip.cs
index 8a66da9..afc03ab 100644
--- a/Liner/Liner/DrawingObjectShip.cs
+++ b/Liner/Liner/DrawingObjectShip.cs
@@ -32,5 +32,47 @@ namespace Liner
         }
         public string GetInfo() => _ship?.GetDataForSave();
         public static IDrawingObject Create(string data) => new DrawingObjectShip(data.CreateDrawingShip());
+
+        public bool Equals(IDrawingObject? other)
+        {
+            if (other is not DrawingObjectShip otherShip)
+            {
+                return false;
+            }
+            var ship = _ship.Ship;
+            var otherShipShip = otherShip._ship.Ship;
+            if (ship.GetType() != otherShipShip.GetType())
+            {
+                return false;
+            }
+            if (ship.Speed != otherShipShip.Speed)
+            {
+                return false;
+            }
+            if (ship.Weight != otherShipShip.Weight)
+            {
+                return false;
+            }
+            if (ship.BodyColor != otherShipShip.BodyColor)
+            {
+                return false;
+            }
+            if (ship is EntityLiner liner && otherShipShip is EntityLiner otherLiner)
+            {
+                if (liner.DopColor != otherLiner.DopColor)
+                {
+                    return false;
+                }
+                if (liner.Pool != otherLiner.Pool)
+                {
+                    return false;
+                }
+                if (liner.DopDeck != otherLiner.DopDeck)
+                {
+                    return false;
+                }
+            }
+            return true;
+        }
     }
 }
diff --git a/Liner/Liner/IDrawingObject.cs b/Liner/Liner/IDrawingObject.cs
index 7422b43..5525b33 100644
--- a/Liner/Liner/IDrawingObject.cs
+++ b/Liner/Liner/IDrawingObject.cs
@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 namespace Liner
 {
-    internal interface IDrawingObject
+    internal interface IDrawingObject : IEquatable<IDrawingObject>
     {
         public float Step { get; }
         void SetObject(int x, int y, int width, int height);
diff --git a/Liner/Liner/MapWithSetShipsGeneric.cs b/Liner/Liner/MapWithSetShipsGeneric.cs
index a17ce92..7e338bb 100644
--- a/Liner/Liner/MapWithSetShipsGeneric.cs
+++ b/Liner/Liner/MapWithSetShipsGeneric.cs
@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 namespace Liner
 {
     internal class MapWithSetShipsGeneric<T, U>
-        where T : class, IDrawingObject
+        where T : class, IDrawingObject, IEquatable<T>
         where U : AbstractMap
     {
         private readonly int _pictureWidth;
diff --git a/Liner/Liner/SetShipsGeneric.cs b/Liner/Liner/SetShipsGeneric.cs
index 13a1be7..e3904d2 100644
--- a/Liner/Liner/SetShipsGeneric.cs
+++ b/Liner/Liner/SetShipsGeneric.cs
@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 namespace Liner
 {
     internal class SetShipsGeneric<T>
-        where T : class
+        where T : class, IEquatable<T>
     {
         private readonly List<T> _places;
         public int Count => _places.Count;
@@ -23,6 +23,10 @@ namespace Liner
         }
         public int Insert(T ship, int position)
         {
+            if (_places.Contains(ship))
+            {
+                return -1;
+            }
             if (Count == _maxCount) 
             {
                 throw new StorageOverflowException(_maxCount);