buns....there shouldn't be any lines. The water should be very black, especially in simulator mode. If you are on the water you will see some cloudiness, depending on how high the sensitivity is and how dirty the water is. The only time I see vertical lines is when running the TM and even then it isn't too bad to read. Maybe you could plug this into another base and see how another transducer works. Otherwise the unit may be bad and need to go for sevice.