public double GetDist(Point p1,Point p2)
        {
            return Math.Sqrt(Math.Pow(p1.X - p2.X, 2) + Math.Pow(p1.Y - p2.Y, 2));
        }

        private void Form1_MouseMove(object sender, MouseEventArgs e)
        {
            double boatrot = 0; // just a test

            Point a = e.Location; // this is the 'player' in this case, the mouse pointer
            Point b = textboxcenter; // the center of the object eg boat, in this case a textbox
            Point c =
                new Point(
                    (int)
                    ((Math.Cos(boatrot)*(0)) - (Math.Sin(boatrot)*(20)) +
                     textboxcenter.X),
                    (int)
                    ((Math.Sin(boatrot) * (0)) + (Math.Cos(boatrot) * (20)) +  // all of this basically makes a third point that is 20 away from the boat, and oppasite the direction of said boat
                     textboxcenter.Y));
            double A = GetDist(b, c);  // just for ease of use
            double B = GetDist(c, a);
            double C = GetDist(a, b);

            double angle = Math.Acos((Math.Pow(A, 2) + Math.Pow(B, 2) - Math.Pow(C, 2))/(2*A*B));

            label1.Text = string.Format("Mouse ({0},{1}) Boat ({2},{3}) Angle ({4}) Dist ({5})", e.X, e.Y, textboxcenter.X, textboxcenter.Y, angle, C);
        }