Abstract: A multiple trim modulation system for efficiently and simultaneously controlling multiple trim devices upon a marine vessel. The multiple trim modulation system generally includes a plurality of trim devices movably mounted to a watercraft and a controller adapted to control the plurality of trim devices. The controller includes a plurality of adjustment modes, wherein each of the plurality of adjustment modes moves the plurality of trim devices in a simultaneous manner. The plurality of trim devices either move towards a similar direction or move towards an opposing direction depending on a corresponding mode of the plurality of adjustment modes.