Because of the use of Grav vehicles, roads are not nearly as important to armies of the Renegade Legion setting. Rivers often become major routes of travel as they are clear of obstructions. Tank battles can also occur far out at sea, as grav tanks fly above the surface of the ocean, popping up from the troughs of large waves and exchanging fire with the enemy forces. However, the altitude limit of anti-gravity is usually several hundred feet, and the top speed is 500 miles per hour at that altitude. Flying a few feet above the ground is safer as grav vehicles are vulnerable to hits from below, and this also slows their top speed as they avoid crashing into terrain.