diff --git a/WarmlyShip/WarmlyShip/DrawningObjectShip.cs b/WarmlyShip/WarmlyShip/DrawningObjectShip.cs
index f0da2a3..1a2ddb2 100644
--- a/WarmlyShip/WarmlyShip/DrawningObjectShip.cs
+++ b/WarmlyShip/WarmlyShip/DrawningObjectShip.cs
@@ -40,5 +40,49 @@ namespace WarmlyShip
 		public string GetInfo() => _warmlyShip?.GetDataForSave();
 
 		public static IDrawningObject Create(string data) => new DrawningObjectShip(data.CreateDrawningShip());
+
+		public bool Equals(IDrawningObject? other)
+		{
+			if (other == null)
+			{
+				return false;
+			}
+			var otherShip = other as DrawningObjectShip;
+			if (otherShip == null)
+			{
+				return false;
+			}
+			var ship = _warmlyShip.warmlyShip;
+			var otherShipShip = otherShip._warmlyShip.warmlyShip;
+			if (ship.Speed != otherShipShip.Speed)
+			{
+				return false;
+			}
+			if (ship.Weight != otherShipShip.Weight)
+			{
+				return false;
+			}
+			if (ship.BodyColor != otherShipShip.BodyColor)
+			{
+				return false;
+			}
+
+			if (ship is EntityMotorShip motorShip && otherShipShip is EntityMotorShip otherMotorShip)
+			{
+				if (motorShip.DopColor != otherMotorShip.DopColor)
+				{
+					return false;
+				}
+				if (motorShip.Tubes != otherMotorShip.Tubes)
+				{
+					return false;
+				}
+				if (motorShip.Cistern != otherMotorShip.Cistern)
+				{
+					return false;
+				}
+			}
+			return true;
+		}
 	}
 }
diff --git a/WarmlyShip/WarmlyShip/IDrawningObject.cs b/WarmlyShip/WarmlyShip/IDrawningObject.cs
index 94af911..0a41158 100644
--- a/WarmlyShip/WarmlyShip/IDrawningObject.cs
+++ b/WarmlyShip/WarmlyShip/IDrawningObject.cs
@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 namespace WarmlyShip
 {
-	internal interface IDrawningObject
+	internal interface IDrawningObject : IEquatable<IDrawningObject>
 	{
 		public float Step { get; }
 		void SetObject(int x, int y, int width, int height);
diff --git a/WarmlyShip/WarmlyShip/MapWithSetShipGeneric.cs b/WarmlyShip/WarmlyShip/MapWithSetShipGeneric.cs
index 209da81..1b0ad57 100644
--- a/WarmlyShip/WarmlyShip/MapWithSetShipGeneric.cs
+++ b/WarmlyShip/WarmlyShip/MapWithSetShipGeneric.cs
@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 namespace WarmlyShip
 {
 	internal class MapWithSetShipGeneric<T, U>
-		where T : class, IDrawningObject
+		where T : class, IDrawningObject, IEquatable<T>
 		where U : AbstractMap
 	{
 		private readonly int _pictureWidth;
diff --git a/WarmlyShip/WarmlyShip/SetShipGeneric.cs b/WarmlyShip/WarmlyShip/SetShipGeneric.cs
index 8a37607..9eb0df0 100644
--- a/WarmlyShip/WarmlyShip/SetShipGeneric.cs
+++ b/WarmlyShip/WarmlyShip/SetShipGeneric.cs
@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 namespace WarmlyShip
 {
 	internal class SetShipGeneric<T>
-		where T : class
+		where T : class, IEquatable<T>
 	{
 		private readonly List<T> _places;
 		public int Count => _places.Count;
@@ -27,6 +27,10 @@ namespace WarmlyShip
 
 		public int Insert(T ship, int position)
 		{
+			if (_places.Contains(ship))
+			{
+				return -1;
+			}
 			if (position < 0 || position > Count || Count == _maxCount) throw new StorageOverflowException(_maxCount);
 			_places.Insert(position, ship);
 			return position;