Ok, so I have a old eagle ff I think it is a fish id 128.. it reads good and has mph and everything Wrks great on the unit. The only problem is when I am running at high speeds it will not read. I have been told that I can put the transducer in the hull to make it read at high speeds. Others say I should lower the transducer so it is a little under the bottom of the boat.

What are my options for it to read at high speeds.

Other than buying a new unit.

Use epoxy and stick it in the hull. You problem should go away

If there is another set of holes in the bracket or a sliding bracket; you might try lowering it first. If you put it inside the back of the boat make sure of the following: lowest point as far back as possible, dry area out throughly, sand a slick spot for it to sit and then epoxy it in. A little bit of work and there still are no guarantees. There may be another transducer for that unit for the inside of the boat; better check and see???

I will see if I can get it lower without drilling holes. Then ill try the inside.

Do I face the transducer forward or face it the same way as it is on the transom.

I hear it stops reading cause air get between it and the water.. is that it??

that's the problem..also with it on the outside it has been known to be damaged by stumps and such..I have never had a problem with one on the inside..some say you lose some sensitivity shooting through the hull, but..???

Mine wouldn't read high speed with it level and below the hull. It would cavitate. I tilted it tail down one notch and it works at all speeds now. Slanting down causes it to drag more in the water removing the cavitation. Depth accuracy was not lost.

I always put mine in the hull. I have trouble at high speeds too and I have run flashers, paper graphs, and LCDs. I normally turn mine off at high speeds 30+. By the time you spot fish on it they will be 1/4 behind you anyway. Never had a use to to run a fish finder at much more that a fast idle.

If you do put it in the hull... ^^^ what Donald said.

Some hulls will create bubbles, cavitation, under them making a hull mount not so good for reading at higher speeds. Lowering a transom mount may or may not be a better option. My through hull reads fine until I get up on a plane then I get a correct depth reading and that's it.

Joe

Be sure to use transducer epoxy like Lowrance or Hummingbird. Stuff like silicon can leave air bubbles and cause a slow signal or not at all. You might can try to place the transducer under you live well area. You should have no problem shooting through. Trying to place it around the bilge/livewell pipes area may not work because some boats have a 2x4 glassed in to anchor the plumbing for the bilge and live well. The transducer will have trouble shooting through it. Having them inside is best not for fish finding, but for depth. I like to know when I leave 20 ft to 2 ft on plane.

All boat hulls create a royal mess as it displaces water at speed. There simply is no smooth spot or "bubble-free" location under a boat or behind it. Following the right RULES and using the right tools can make all the difference. It's a learning curve.

Silicon remains pliable and "rubber-like" creating insulating properties. Any adhesive medium, soft, rock-hard, etc., used to bond a transducer to the inner hull, creates greater density (in addition to the density of the hull) most often adding to other issues which render a sounding less than designed. Most who stick it inside the hull do so to avoid damage to the transducer fishing stumps.