Help positioning fish finder transducer.

[eddiebhome]

Maybe you more experienced folks can help me out here. When I got boat a few weeks ago it had a transducer attached on the back of the boat but no fish finder electronics. No problem because I already had a Garmin 160, which I really like. Anyway, I pulled the old transducer off and placed mine in the same location, figuring the guy who did it before I owned the boat knew what he was doing, or at least knew more than I did. Anyway, as per the manufacturer, it is level with the water line and sticks below the bottom of the boat about a centimeter. Yet, when I get over about half throttle I lose the signal. I guess it's getting air up under it. Do you think it's too close to the motor, or too close to one of the keel ridges under the boat. I've already moved it once and don't want to keep drilling holes in the back of my boat. Help!!
Thanks,
Eddie

[mistertwister]

All of the transducers that i have installed suggest keeping the installation point at least 15 inches from the motor. Sounds to me like when its on plane it experiences the problem. I would make sure that it is clear of any keels and at least that distance from the prop. You might try Garmin's web site and see if they have any suggestions. Maybe some others on here have some suggestions?
Good Luck!
Twister

[Majesticman]

If it is fiberglass mount it inside the boat.

If it is aluminum let me know what to do. Mine works fine at low speed but goes to #### when I hit 20. Some say the flat bottom traps air and others say rivets cause it but I don't have rivets. I have a friend that has a john and his works all the time and we have the transducers in the same place. Go figure.

I hear of transducers that will mount inside aluminum so I am going to check them out.

[magnum500]

You are probably having trouble with cavitation. What happens is air gets mixed with the water and the air causes the transducer to not work properly. Make sure the tranducer is between any ribs on the underside of the boat. If it in line with or close to inline with a rib it will cause the cavitation that causes this problem. And yes being too close to the motor can also cause this problem. I speak from experience!!

[sac-a-lait]

I only use mine on the rear for temp and depth readings...When I want to really see the bottom, I switch on the upper unit and drop the TM in...IT has a TD mounted on it and I can see whats in frount of me, not behind me.

[izzysfishin]

I only use mine on the rear for temp and depth readings...When I want to really see the bottom, I switch on the upper unit and drop the TM in...IT has a TD mounted on it and I can see whats in frount of me, not behind me.

I've had graphs and locators on numerous boats aluminium and glass. On the glass boats the TD shot through the hull. On aluminium, some worked fine and others i could never get right at planeing speed. Sac, you hit on a subject that has allways befuddled me. Why run down a lake 50 or 60 mph with your graph on, when what your looking at is allready 200yds behind you. Call me a skeptic, but i don't see how any locator can give you an accurate picture at 60mph. A buddy proved that theory while running the Missouri river, by the time his locator showed him out of the channel he was 50 yards up on a mud flat. Maybe neither one of us knows how to set one up for higher speeds though, i generally get a good map and check out the spots i want idling around...izzy

[KCBH]

On my old basstracker I mounted the 'ducer in the correct location from the prop , then I raised it up level with the bottom of the boat and used silicone to seal off the gap between the 'ducer and the boat.

It worked for me ...