Existence of solutions of orientor elds with non - convex right - hand side

A toy object such as a submarine or the like with a ballast chamber and an air chamber dimensioned such that normally in a static position the body floats in water with only a small portion of the body extending out of the water. The ballast chamber is filled with water and the air chamber is buoyant and causes the top object to float. Diving planes extend outwardly from the body such that when a motor is activated the toy moves forward, submerges and stays submerged so long as there is forward motion. When the motor stops the toy object rises to its static position.