My airmar P66 transducer is acting up. It is five years old and has always worked generally well. It would occasionally lose bottom for a few seconds and then restore itself so no big deal. It is networked to a Raymarine C-80, mounted as recommended by the manufacturer and Raymarine and the only problem is depth. It shows speed accurately as usual. Over the last few days we have been on the water for several hours at a time running at 15-17kts. The transducer, (Triducer according to Airmar since it does depth, speed and water temp.) loses bottom for several minutes at a time, 5-15 minutes, and when it recovers sometimes shows a false shallow depth, i.e. 33 ft when we are in 500ft of water, before blanking again then showing an accurate depth. This happens mostly at cruising speed and it seems to work properly at low speeds or when we start off from a prolonged halt. I have changed sensitivity, switched from auto to manual for lock, tried both 50 and 200 KHZ, etc. I have switched off the power to the DSM300 Raymarine depthsounder unit and have gotten a warning on the C-80 that depthsounder signal is lost so I know the DSM300 is outputting a signal. I have not yet done a factory reset as I can't get on the water for a few days and want to do it underway. The DSM300 is not where I can watch any lights for error codes (unless I stand on my head!). Has anyone had similar problems? All ideas are welcome. And...if a new transducer is in my future shoud I just replace the P66 or go for something new. I am not much of a fisherman so don't need to count scales.
Thanks.