What about using a relay contact in the design for a set of hold contacts. Use that in conjunction with a momentary switch for the light. When you run the rigger up or down, you push(and release) a button and the light comes on, and stays on until the down rigger is turned off. The hold contacts of the relay keep the light on. If you went up to a rigger and you wanted to see what depth it was set at, you push the button, the light comes on. When you release it, it goes off.