# Losing the bottom at speed



## PBsQuest (May 26, 2013)

I have a 26’ cruiser that I had a Garmin installed last year. The transducer was mounted to the same hull saver block the old one was in. I lose the bottom above 10 mph. Is it as simple as lowering the transducer or is there something else I should be considering? The old unit didn’t have the same issue. It’s a fiberglass hull if that matters. 


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## Whitefin (Sep 4, 2008)

Something is blocking the flow of water at speed. Possibly mounted too high or behind a strake. Make sure it is angled slightly forward (about 5 degrees.


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## Meerkat (Aug 10, 2008)

When you lose bottom, turn to the side where your transducer is located. If you pick up bottom again your transducer is too high. As far as attitude of transducer is concerned, back end of transducer needs to be angled down about 3 to 6 degrees from plane of the hull. 


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## PBsQuest (May 26, 2013)

Meerkat said:


> When you lose bottom, turn to the side where your transducer is located. If you pick up bottom again your transducer is too high. As far as attitude of transducer is concerned, back end of transducer needs to be angled down about 3 to 6 degrees from plane of the hull.
> 
> 
> Sent from my iPhone using Tapatalk


I haven't noticed it picking up the bottom if turning to starboard. I may have to try and lower it and adjust it down. Once it goes in the water I won't really be able to adjust it again unless it gets pulled out of the water. 

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## joekacz (Sep 11, 2013)

Take a straight edge and lay it on the hull…slide it back to the transducer…you then can make sure that your transducer is either flush or below the bottom line of the hulI not above…if it’s flush AND it’s pointed forward with a few degrees towards the bow then maybe lower it a touch below the hull but make sure that your angle is forward or at any kind of speed your transducer will miss the return signal…also if there’s a ping adjustment on your sounder you may want to adjust it higher while your running…this is the way that I do it but I’m sure that there are some other variations of the final adjustments…IMO and good luck 👍


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