A method and a device for computer-aided regulation of rotational speed of a reel spool, when paying out (and reeling in) an on-wound line. The line surface is surveyed by digital imaging and/or an electronic distance measuring device and incidents of line rising from the spool are captured and reported to an on-board computer which, proportionally to such input, orders variable engaging/releasing of braking force to the brake(s) of the reel to avert backlash.
