I started off with the X2 model which has a transducer that connects to your downrigger cable and it uses the same prob as the X4. You don't have to worry about mounting a transducer to your boat, and you can save yourself a couple hundred dollars. You will be amazed how different your speed can be at your cannonball compared at the surface on some days. Same goes for the temperature. With the Fish Hawk you will be able to consistently be in the most favorable temperature, and keeping your gear moving at a favorable speed. Yes there will be days the fish will be out of temp, and like a different speed, and you will know that and be able to keep your gear in that zone, catching more fish.