Interesting dynamic: Clear everything but 2 beach balls by butting them out using the icebergers. Then, roll them at each other at the same speed against the ground with two fingers, and release once they hit the water. Since their X velocity is determined by their rotational velocity(divided by 360), they have virtually no friction with each other. But unlike two free floating bodies in space that are at a constant motion, when they collide, they try to go past each other instead of the faster, more massive one winning(the velocity of the new body is the faster minus the slower).