wayne i believe you have a trailcraft like myself and i had the same picture on my lowrance, check if there is a water intake in the hull for a killing tank up near the bow, , the lines are from air bubles on the surface so you can up the surface clarity on the sounder settings and the air bubble run straight down the hull from the water intake and across the transducer, i moved my transducer away from the mounting bracket and thosse horizontal lines stopped, i then found i was getting to much interfernce from the motor( prop noise ) and i coudlnt run my sensitvity above 45 % and get a clear picture. you can try and mount the transducer on the other side of the motor as far awy as possible or i ended up installing a through the hull flush mount 1mt in from of the motor.  i can run at 30 knts and 70 to 80 % sensitivity and have clear reading in 50 + mts

Looks like bubbles under the transducer. . . If all else fails buy a Furuno :-)

Looking at the top of your normal sounder screen its definitely showing a heap of interference on the surface.  Bubbles!!  Either something is throwing dirty water over the transducer face from a chine or skin fitting or transducer is in the wrong spot.

cheers 

maybe as all others have said its mounted too high, as on my furuno i can get clear pics doing 30 knots

does this only happen at high speeds,

does it happen when just ideling around or stationary

does it happen with engine off

maybe the transducer is mounted too close to the engine causing it to catch whitewater

thanks for the replies,



JustDhuit - yeah I have a kill tank up the front which you can fill via an internal bung so I assume there is an intake under the hull (will check though).  You mentioned that you moved your transducer away from the mounting bracket - did you just move it to the far right side of the mounting bracket or did you take it completely off the bracket and mount it directly on the hull?



You also mentioned mounting it on the other side of the engine - would it make much difference doing this?



I haven't heard much about those hull flush mounts - where did you get this done?  Do they cost much to install?



marbles - I went to buy the Furuno620 though couldn't fit it on the console, nor under the garage door - so had to comprimise;)



PGFC - what do you mean by a "chine or skin fitting"?



Sorry for all the questions fellas - have spent a bit of $$$ on this sounder so eager to sort it out...



cheers



Wayne

He means the transducer is is in a noisy spot, ie; behind in some hull feature causing turbulence.

wanye , i tried a few places , i put the transducer on the far RHS of the stern mounting bracket to get out of the path of the air bubles coming from the water intake which lines up well with the rear mount bracket. although as i said i had prop noise to deal with as well , you can relocate the transducer to the port side and fix straight through the transom but i went back to all boats and purchased a flush/ skim through hull transducer, you have to lift the inspection hatch and drill 40 mm hole in bottom of hull and re seal.  i would first try moving transducer far away from wwater intake and dropping the unit down as far as possible to try to allow air bubbles under hull to travel over the top of the unit rather than under the face, you will have to watch transducer on any beach launch that it may hang down and get damaged

Sorry no help with the sounder...but I gotta say I like the decent amount of room at the back there - would be handy for diving.

Do just as Mr Dhu it says  mate. Mount it as far away from the motor on the mounting bracket as you can. I had to do this on my trailcraft with my furuno. I personally think they stuffed up with the placement of there bracket

its interference as has been said.

take transducer off and go for a run . 

look over transom while on plane and look for clean water at least 300mm away from motor leg.

mark spot and re mount transducer.

should be a great little unit. i had the lms520 and it read bottom very well at speed

how does the pic look with motor off at anchor????

Interesting Post, I have a similar problem with my HDS unit, I have the HDS10, the funny thing is that I am using the same mounting spot as per my previous unit (LCX112) and had no problems with tranducer mounting until now. Seems that the HDS models are more sensitive in picking up bubbles - thanks

Looks like the transducer is creating turbulence. I would move the transducer higher up so that the bottom of the transducer is parrallel to the hull (turning the mounting bracket 180 degrees could help)

thanks for the replies guys...  hmmm not sure what to do now -

just dhu it says to move it down, JohnSorrell says to move it up:)



I think i'll try a couple of positions and see what readings I get...i'll post back to let ya know how I go.



just dhu it - how much did that "flush/skim through hull transducer" set you back?  If I can't get a good reading I might look at installing one of these...

wayne the flush, through hull transducer was around $280.00 .

height of transduce as per John, the tranducer has a ring/joint around it and that should be level with the bottom of the hull,  run a straight edge along the underside of the hull and try and angle the joint to be the same as the straight edge or better still with the rear end slightly down, watch out for any stringers along the under side of he hull which will cause turbelence, but with alli hulls and possibly the water intake for the fish box there will a constant stream of air bubbles travelling along the underside of the hull and the transducer face. this is exactly the same problem i had with mine so another option to try would be to drop the transducer as low as possible to allow any air bubbles to go over the top of the transducer and cause interference,  one thing to prove this would be at anchor the problem will stop and recieve a clear picture, also what sensitivity are you running at because this adds to the fault , i can now keep mine up at 70 /80 %.

If you go the skim fitting just keep away from the keel or any stringers as they have have disturbed water coming off them and you need to keep 70 + mm away

Also make sure the transducer is more than 400mm from the centerline of the hull...