Re: Your opinion please...
I installed my Humminbird Fishfinder and the transducer, and as it was my first installation I read carefully the manual. I wanted to avoid something that I saw in another boat: the sonar lose signal when the boat is moving fast. Well, the Humminbird manual is very detailed when talking about transducer installation. It says that the unit works fine at speeds from 0 to over 70 mph, but it all depends on the installation of the transducer. As mentioned above, it is very important to locate the transducer in an area which is relatively free of turbulent water. Avoid places near strakes or rivets, and it says that for outboards it is best to stay at least 15 inches to the side of the propeller(s). Another consideration is the angle of deadrise. The transducer when mounted should point straight down. For the Humminbird transducer, if the deadrise angle is greater than 15 degrees it will be necessary to angle the transducer slightly, but keep in mind that the area covered will be somewhat to one side of the boat. The manual provides a cardboard template to drill the holes for transom installation ensuring the correct angle. The manual also explains the inside the hull mounting method, as the transducer that came with my Humminbird can be transom or inside hull mounted. I opted for the inside the hull installation, as I wanted to avoid damage because of hitting the transducer with the forklift at the marina or with the bottom at the beach or shallow waters (indeed, that happened to the previous transducer). For inside the hull installation the same rules apply: selected area must be free of turbulent water on the outside (avoid ribs, strakes and other protrusions), select a point close to the centerline of the hull and near to transom, as this area will be in contact with the water at high speeds. For inside the hull installation the manual recommends (and that is exactly what I did) to mount the screen unit and then connect the transducer cable, laying it free on the deck and test placing the transducer unit in the bilge area without glue. It is recommended to put a small amount of water in the bilge so the transducer remains submerged. This avoids air to be between the transducer and the hull (signal can not travel through the air). You can use a small bag with sand to keep the transducer in place. Then you can test different places at low and high speeds, and select the best location. Once selected, use a slow-cure, two-part epoxy. NEVER USE SILICONE OR ANY OTHER SOFT ADHESIVE as it degrades the signal considerably.<br /><br />My unit is working fine inside the hull. If you want, send me an email to
kesh@cantv.net and I will scan and send you the manual pages. It is very detailed and worked great for me.