Works with all makes and models of downriggers. Most species of fish are temperature predictable. There are specific known preferred temperature zones that fish will sense and go to. Locate the correct temperature zones and you have access to active feeding fish. With the Fish Hawk 840 you know the water temperature at the surface and the depth of your lure while trolling to 200 feet deep.
Lure speed is the key to proper lure action and presentation.
The Model 840 displays both the surface and downrigger lure speed. You can adjust your lure speed for wind, wave action, surface currents and underwater flowage to 200 feet of depth. The special sensors for the temperature and speed at the surface and the downrigger, continually relay data to the microprocessor. Data can be displayed in Fahrenheit or Centigrade and MPH or Knots. No modification at all - to any made or model downrigger ever created.