Humminbird depths all wierd...

[Andy in NY]

Okay, I've only had the boat out twice, and yesterday was the first time I had to really open it up. I have a humminbird 525, and when I got out to the middle of the lake and was at WOT (about 25mph) the depth readings were REALLY crazy... would go from 800ft to 3 ft to 600 to 300 to 900 to .8 to 5, etc. changing REALLY fast. I know for a fact that the deepest part of the lake is less than 100'. What gives? at slower speeds it was fine.

 

[rndn]

Re: Humminbird depths all wierd...

Either your transducer is pointing too far towards the rear of the boat, or it just can't keep up with the speed. I would lean towards the mounting angle of the transducer.

 

[Andy in NY]

Re: Humminbird depths all wierd...

Either your transducer is pointing too far towards the rear of the boat, or it just can't keep up with the speed. I would lean towards the mounting angle of the transducer.

So where do I start to try to adjust it?

 

[rndn]

Re: Humminbird depths all wierd...

Try adjusting it so as it sits in the water it points slightly forward. Your mounting kit should have come with a wedge if needed for the adjustment.
Randy

 

[Andy in NY]

Re: Humminbird depths all wierd...

Try adjusting it so as it sits in the water it points slightly forward. Your mounting kit should have come with a wedge if needed for the adjustment.
Randy

It was on the boat when I bought it. I don't know what you mean by "slightly forward"...

 

[bruceb58]

Re: Humminbird depths all wierd...

It is very possible that you won't be able to rely on your depthfinder when you are on plane. It depends on the your hull and if the transducer is in clear water. Air bubbles and turbulence may be caused by hull strakes and other hull designs. If you can, have someone run the boat and look over the stern to see how clear the water is as it leaves the hull. You may have to move the transducer to an area that has clear water.

 

[gstanton]

Re: Humminbird depths all wierd...

Mine does the same thing. I figure if I'm up on plane, by the time the H'bird shows shallow... I'm already into it! Works fine at slower speeds - at that speed I can actually respond to shallows.

I do have a Lowrance depth sounder and it works fine at plane. Separate transducer.

 

[Wvawitrado]

Re: Humminbird depths all wierd...

I have a eagle fish finder doing the same thing I adjusted the transducer slightly towards the bow meaning if there were a vertical line from the transom to the bottom of the lake the line of the transducer barely would cross is towards the bow side of angle..... very small but makes huge difference in capability and sound readings......

 

[rndn]

Re: Humminbird depths all wierd...

It was on the boat when I bought it. I don't know what you mean by "slightly forward"...

As the boat sits in the water, the transducer is aimed toward the bottom. The flat bottom of the transducer should be parallel to the lake bottom. If your is angled so the transducer beam is aimed slightly toward the rear then your boat may be past the return echo by the time it bouces off the bottom and returns to the boat. If you aim the transducer so it will send the beam slightly forward then your boat will still be over the return beam. My Baja when going full speed, 64mph, would not be able to pick up the return signal in anything over 50 feet of water. I then agled it forward and was able to read depths to 250 feet before losing the signal again.