Depth Sounder Not Tracking Depth At Speed

[bowrider540]

This is my first thread so hope it all works out. I have just purchased a Bowrider 5.4m and a Humminbird GPS & Sounder 787c2 very clear but have a small or BIG problem I cannot get it to track depth at any speeds over about 15km/hr wich is a pain as you not even on the plane at that speed.

Can anyone offer any suggestions the whole setup was installed by the marine dealer who i purchased the boat thru they are 800kms away now.

I was possibbly thinking that the transducer is not positioned right but dont know how to test this or fix it.

Any help would be great.

[Blackened]

G'day

If the "bottom" on the screen is broken and distorted with the depth flashing, it's caused by a broken signal from the transducer,

Chances are the transducer will have to be either angled a touch forward, set deeper or both.

Before any advice is taken on, best bet to post a picture of the setup from side and behind

Dave

[Angla]

Welcome bowrider 540, Sounds like you are either getting dirty water past the transducer or the transducer is at the wrong height/angle.

The transducer should not be positioned directly behind a strake on the hull or too close to the motor. These things can give off air bubbles that stop the transducer from working clearly.

The mounting position should be roughly centred in line with the lowest part of the hull and tilted downwards about 5 degrees at the rear.

Hope this gives you somewhere to start looking

Chris

[Poseidon]

Your transducer may not be deep enough or has turbulence causing air bubbles to race across its face.

Try moving it a little deeper to get into water less affected by turbulence. What works for me is to have a decent angle on the transducer, allows me to read bottom at all speeds.

I think just about everyone has had dramas getting the sounder to read at decent speeds, it takes a bit of trial and error however you will find the sweet spot and keep it locked there.

Attached is a photo of the angle on my transducer, hope it helps.


Regards Cameron.

[bowrider540]

Thanks guys I will try a slightly different angle it seems pretty flat at the moment will try getting a pic of it tomorrow. when travelling at seeds lower than 15km/hr it is reading very well just not any fatser than this i thought it should thats all

[backlash08]

Also give the dealer a call if you havnt done so, they might have ideas with that specific hull/transducer combo - good luck with it - Craig

[bowrider540]

Welcome bowrider 540, Sounds like you are either getting dirty water past the transducer or the transducer is at the wrong height/angle.

The transducer should not be positioned directly behind a strake on the hull or too close to the motor. These things can give off air bubbles that stop the transducer from working clearly.

The mounting position should be roughly centred in line with the lowest part of the hull and tilted downwards about 5 degrees at the rear.

Hope this gives you somewhere to start looking

Chris

Hey chris the guard in your pic does that help with quality and results

[Local_Guy]

sounds to me like your sounder needs to be lowered more in the water.... i find this common with the humminbird units and if you drop it another 1cm that should fix your probs.

with Poisiden's transducer angle, it is probably a little to much down. 1/2 that angle to horizontal would be just about perfect.

[Davey1]

Hey mate,

Have a look at this installation manual. Different brand but it helps explain the principles involved re locating the transducer. If you loosen the mounting screws for the transducer make sure you have a tube of good marine sealant ready before you rescrew. Sikaflex is good, about $13 at a marine shop.

I had the same problem when I got mine installed. After having problems like yours I read the manual & it soon became obvious that the useless dealer had just attached the transducer to the back of the boat with no thought as to whether it would work.

http://www.norcrossmarine.com/customer_service/Manuals/8000-01(TM).pdf

[fez]

Bowrider,

the guard Angla has a photo of is to stop spray from the transducer getting into the outboard. Some set ups need it others don't.

Cheers,
Fez

[mattyd]

Bowrider - I'm in the same boat as you (pardon the pun!). I've just picked up my boat a few weeks ago (Freedom Escape 5.3m) and I could not get a reading on our first trip out once it got up on the plane.

I've got a Navman 4433 sounder / fish finder and I've got to do a lot more homework on this baby to find out what it can do.

I took it out from Scarborough (Brisbane) on the public holiday a couple of weeks ago and it really was too rough for any sounder to work. The boat was out of the water over the top of 4-5ft swells (just v. keen to get out at that stage...really wasn't good weather for boating!!). But as I got into some smoother waters, I still couldn't get a reading. I really wanted to find out the top speed of the the 90hp ETEC on the back.

I will study the manual as well as Davey's PDF he attached above. Let me know if you have any joy after adjusting transducer angles.

Matt

[Spaniard_King]

sounds to me like your sounder needs to be lowered more in the water.... i find this common with the humminbird units and if you drop it another 1cm that should fix your probs.

with Poisiden's transducer angle, it is probably a little to much down. 1/2 that angle to horizontal would be just about perfect.


IMO Local guys advice is very good. Most transducer problems associated with speed can be fixed by lowering the actual transducer further into the water.

Transducers rely on picking up the signal on its return (this happens at a faster rate than you can imagine) so the best angle is level with the hull as thsi will be horizontal in most cases at rest. When you are on the move you are most likely to be traveling nose up therefore your transducer will be angled forward.. if you are to increase this angle you are most likely going to miss some signal returns.

If you doubt me answer this, Why do transducers that are mounted inside the hull work so well at speed.. ie more than 30 knots;D

[finding_time]

Posidon

Mate you pic looks far from ideal to me mate,. How does it read? I would drop it down a cm or 2 and level it out as it appears to be tipped to far foward!

[dreemon]

I tryed what Blackend said to angle the trans foward, and it worked !! I get depth readings at all speeds now:D thanks !

[bowrider540]

Thanks for all the help guys. The guys who installed it must have just slapped in on the middle of the transducer mounting plate. got around to checking measurements etc and found it was way to high the botom of it was level with the bottom of the hull. Lowered the whole unit about 2cm and tsted and now have full readings right through the speed range of the boat. Thanks again everyone has been a great help.

Now I just have to get some good weather on my days off to get out on the water - want to head out to Keppels etc not sure really would love to get some snapper fishing in. Looking forward to getting on the water.