I have a problem with my Humminbird 100-SX - it is loosing the depth range or signal at high or cruising speed, my boat is made of aluminium with 5 keels or strakes, previously - last year the transducer was mounted almost in line with the outter starboard keel and I was loosing depth signal. This year I made the installation as per the manufacturer I installed the transducer: 17 inches from the prop, in between the middle and the second keel and at the specified height on the transom. Guess what still loosing signal any trick you know to prevent that will help !! I know Humminbird it is not the top quality, but a friend of mine has an Eagle Fish Easy II and it is doing the same as mine, so is it because none of the low end can keep depth signal ?<br /><br />Thanks<br /><br />Smoky