A contour follower includes a plurality of sensors spaced around a waterjet nozzle, each of the sensors being configured to measure a distance between a working surface and a first plane, perpendicular to a longitudinal axis of the nozzle. The sensors may include hall-effect sensors lying in the first plane and magnets lying in a second plane, parallel to the working surface. A detecting circuit processes signals from the sensors to determine an angle of the working surface, relative to the first plane, and a distance between an aperture of the nozzle and the working surface. A collision detection sensor provides a signal in the event the device approaches to within a selected distance of an obstruction in the plane of the working surface. A shield plate blocks and dampens secondary spray-back of cutting fluid occurring at low angles above the working surface.