just installed a lowrance x-88 on my 16' westcoaster. low speed depth seems to be right on, but when i get up to about 20 - 22 mph the unit seems to lose bottom. in water i know to be about 40', it will read anywhere between 100 and 1200 ft!. when i slow down to about 10mph, the wrong depth reading will start flashing, and then go down to the correct depth. i am using a 200 khz-20degree single transducer, not the dual frequency transducer. anyone out there know how to correct this problem? thanks in advance....captn-tin
