Depth Finder Problem when traveling

[Doug Stanek]

just mounted a new hummingbird 565 depth finder. located transducer on transon in right corner, bottom of transudcer is even with bottom of the boat. It works great except when moving fast (above 10 mph). then it gives wild readings. any idea on what is causing this?? any remedies? my old unit did the same thing. my boat is aluminum, can I mount the transducer on the inside bottom of the hull or will this not work either, thanks

 

[TrepMan]

Doug - you can not mount that transducer in the hull, though there is a company (don't remember the link right now) that does now make a transducer that can read through an aluminium hull.



I'm sure Greg from Humminbird will jump in soon, but first thing to look at is A) is it far enough down into the water when you are running and B) is it in a place getting a clean running surface?



I had to move mine as low as it could go to keep readings at 30mph, and it still blows out a little on very choppy water.



Trep

 

[Steven Parker]

You're having a problem called cupping. A pocket if forming behind the transducer causing wild readings at high speeds. Try adjusting the transducer to point at more of a downward angle. If you are at 90 deg. now try pointing it down 10 deg. Make small adjustments and give it a try. If it doesn't work adjust again.

 

[William Birkett]

Does the boat have a stepped hull??? Is there anything further up the hull that would cause disturbance in the water at higher speeds???



Take a look at my McGyver bracket and see if something like this might help you overcome the lack of clean water for your transducer... The craziness you experience may be the result of disturbances you didn't know existed at higher speeds.



Tight Lines,

 

[Humminbird Greg]

Trep,



Jump!





Doug,



These guys have given you some good advice. If you used the transducer mounting template, the bottom of the transducer should end up just a bit lower than the bottom of your boat. If it

 

[Jim in VA]

Wow! Thanks guys!! I wasn't the original poster but have been having the same problem. Thought it was something that I just had to live with - unlike the original poster, my Humminbird would just start to read "0" feet when I got up past 10mph. Now that I know there's a fix, I can't wait to try it this weekend.

 

[William Birkett]

My fix has worked great... While I completely understand some of the comments I got about having depth data that you can't react to when you are hauling a boat load of butt... It is nice to see and confirm when I happen to stray outside the channel lanes and starting inching towards thinner water... My McGyver fix was FAST, CHEAP, and effective... I wonder when the designer's will realize the standard location does NOT work...



Tight Lines

 

[Jim in VA]

Bill:



Nice fix! I've got a factory (or is it dealer?) install where the Humminbird transducer snaps onto a plastic mounting plate bolted to the transom. The set up is designed to allow the transducer to come off the plate in the event of an unexpected encounter with a log or other flotsam.



How did you rig up the McGyver fix? It looks like some metal brackets with a whole LOT of washers on the upper side of the arm holding the transducer. Did you fabricate the arms yourself? I'm thinking of switching mine to something like that if I can get readings at speeds.



Thanks in advance!