I ordered a splitter cable and puck style transducer for my Humminbird 797C2 si so that I could get thru hull high speed readings as well as still having the other transducer for Side Imaging. The splitter ( $20.00) has seperate pins that use the thru hull puck style transducer ($80.00) for down sonar and other pins for the side imaging sonar automatically without a switch . The system works unbelievably well .... I had my boat on a lake with over 300 ft of depth and NEVER lost bottom readings at any speed or any depth. At 75 mph with the the lake bottom changing quickly my 797 never lost bottom as well as marked lake trout suspended 75 - 220 over 300 feet . I even tried shutting the unit off at over 70 mph and as soon as I powered it back up it read bottom perfectly. I feel that this unit will save you props and gearcases as well as find you fish. My Lowrance LCX-25 was not reading bottom at all after I got on plane and deeper than 40 feet. This Humminbird performs like we all wish a sonar should. --- mike