Garmin GPSMAP 188C Owners Manual - Page 107

Proper transducer installation is key to getting the best performance from your new unit. If the transducer lead is too short, extension cables are available from your Garmin dealer. DO NOT cut the transducer lead or any part of the transducer cable, as this will void your warranty. The cable cannot be spliced and connected to any existing (Garmin or non-Garmin) transducer cables. Following are some tips and basic installation instructions for some popular transducers. Detailed installation instructions are provided in the transducer kits. Some transducers may need to be installed by a professional marine installer. Transom Mount Installation Transom Mount Transducer (depth/temp) Appendix A Mounting the Transducer , DO NOT mount the transducer behind strakes, struts, fittings, water intake or discharge ports, or anything that creates air bubbles or causes the water to become turbulent. It is important that the transducer be in clean (non-turbulent) water for optimal performance. Apply marine sealant to all screw threads to prevent water from seeping into the transom. Mount the transducer cable cover well above the waterline. OK Transducer should extend 1/8" below fiberglass hull or 3/8" below aluminum hull Make sure that the transducer is below water level when the boat is on plane at high speed Do not mount transducer directly in the path of the prop. The transducer can cause cavitation that may degrade the boat's performance and damage the prop. 97 Mount the transducer parallel with the bottom.