The problem of penetrating through nets and other objects is solved by cutting the object using various cutter systems, which include, for example a track and a moving carriage containing a cutter, a stationary carriage with a fixed or rotating arm, and/or abrasive cutters. The object is cut by a severing, slicing, or wearing action caused by a moveable blade or abrasive surface. An underwater vehicle incorporating an embodiment of the cutter system can cut a sufficiently large opening in the object to allow the vehicle to pass through.