GENETRON
12-01-2001, 07:30 PM
RICK ASKS A QUESTION ABOUT LOWERING HIS TRANSDUCER AND TRYING TO SHOOT TO THE SIDE.A GOOD QUESTION THAT WE GET ALL THE TIME. THE ANSWER IS GENERALLY A QUALIFIED NO!!SIDEFINDING TRANSDUCERS MUST HAVE A VERY NARROW CONE ANGLE(SEARCHLIGHT BEAM}VERSUS A WIDER BEAM IN ORDER THAT THE SIDELOBES OF THE CONE ANGLE DO NOT TOUCH THE BOTTOM OR AN UNDERSIDE OF A WAVE CLOSE TO THE BOAT. IF IT DOES TOUCH IT WILL SEND BACK A FALSE ECHO PREMATURELY. THEREFORE MOST SIDEFINDING TRANSDUCERS HAVE A VERY NARROW CONE ANGLE TO AT LEAST GET SOME DISTANCE FROM THE BOAT.OBVIOUSLY YOU DO NOT WANT IT TO SEND BACK AN ECHO THAT YOU MIGHT THINK IS A FISH WHEN IT IS ACTUALLY SOMETHING ELSE(BOTTOM OR WAVE).IN SHALLOW WATER THIS CAN BE A HUGE PROBLEM WITH A TRANSDUCER THAT IS PERMANENTLY ATTACHED TO THE BOAT.IF YOU CANNOT CONTROL THE AZIMUTH OF THE CONE ANGLE YOU ARE SEVERLY LIMITING THE CAPABILITY OF WHAT YOU ARE TRYING TO ACCOMPLISH(FIND FISH).WITH ANY SIDEFINDER THAT HAS A FIXED TRANSDUCER THE MOST IMPORTANT THING TO REMEMBER IS THAT YOU ARE "SEEING" A VERY VERY SMALL SLICE OF THE TOTAL PIE{WATER AROUND YOU}!! EXPENSIVE SIDE FINDERS SOLVE THIS PROBLEM BY HAVING A MOTORIZED TRANSDUCER CONTROLLED BY A JOYSTICK. THE OPERATOR CAN THEN SWEEP AN AREA BY MOVING THE TRANSDUCER IN ALL DIRECTIONS!! THIS IS DONE OFTEN IN DEEP WATER FISHING APPLICATIONS.REMEMBER IF YOU CANNOT MOVE THE TRANSDUCER YOU MIGHT BE MISSING HUGE AREAS THAT MIGHT BE HOLDING FISH.ANOTHER BIG PROBLEM IS THAT IF YOU ARE IN ANY KIND OF WAVES THE ROCKING OF THE BOAT WILL MULTIPLY THE NUMBER OF FALSE ECHOES MULTIFOLD. DICK KNUTSON GENETRON