With problems with there 1kw trannies lately. I reckon 99% is the position of them. I've got the exact same set up as you except a 587 and mine is fine at any speeds and can pick up bottom out into the 200's no prob. Send me a pm and i'll send through a few picks of mine to compare with yours.

Chris.

bave to agree I've got the 588 n same transducer and reads fine at speed and no worries out in the deep past 200m. Post some pics up mate much easier to see if it's too high or low etc

 Pics added cheers lads

on here who are absolute gurus but to me it seems set to high mate. In fact I'd say way to high. 

 it's easier to see if it's mounted properly when the picture is taken from behind the boat with the hull flat in the picture.  So you'll need to kneel or lay flat on the ground.  This will then show how deep the transducer sits under the hull 

 I got the 587 and tm260 and im still playing with mine but i have it mounted on the other side

 I reckon you've got the tranny on the wrong side too and far too high. Someone may correct me but you only put the tranny on the port side if you have a counter rotating prop. Once you start getting up to speed you will be getting big water disturbance from the prop.

And like bradz said if possible chuck it on the starboard side.   

definately to high mate, as a indication, the leading edge of the tranny should sit about an 8th of an inch lower than the hull and the trailing edge slighty lower than that. by the pic it looks higher than that and you will be loosing soundings due to there not being any clean water for the tranny to run in.

 Cheers for the replys lads, i am pretty pissed off as i would have thought a boat shop would have know how to fit one properly.

I will have a crack at fixing it my self when i get back from work, I guess next question is whats the best way to plug holes in a fiberglass hull? 

 you may be able to lower the bracket just by loosening the screws..  But if you want to plug the holes I'd suggest you use a 2 pac epoxy..  

All holes in a glass boat should be drilled out oversize, filled with epoxy then drill the epoxy to size, as fibreglass absorbs water if just a screw or bolt is placed thru it and the hull will rot 

Yeah I have mine on the other side of the motor aswell.i installed mine myself using straight edge etc... Like how Robert mc explained.
I can pick up bottom and depth doing an easy 20+ knts.
Take it back to the shop who fitted it!!!!

 hard to believe a shop with so called professional installers would mount it in the Port side as the instructions clearly state Starboard side on a normal trailer boat and give exact heights to mount it. Did mine myself and works great, There is wedges in the packaging so you can get the angle just right as well    cheers ACE

 Only reason to mount that side is if you had a left hand rotation outboard. You don't.

I have same setup. its not perfect yet but i can def sound at 20+kt. i dropped mine 10mm and it made a huge difference!

Watched Mattb84 have all sorts of issues with his to start with, but he mounted it lower and used the wedges to angle it down. Now no problems.

I get your fustration, with so called proffessionals at boat shops, its fustrating that you invest 3K or so on a sounder packege only to have someone cock it up.  

 As Ben just said mate had heaps of dramas with getting mine rite. But in my opinion you are on the wrong side. The trannie needs to be around 10 mm lower than the hull and leaning slightly forward by using the wedges supplied. If I was you I'd be goin back to the boat shop having them repair your hull and goin somewhere else as they have no idea what they are doing. Hope this helps mate pain in the ars I now but you won't look back

looks too high and needs to be tilted down at the back , my 588 is only using a p66 and it is fitted on the port side, it was fitted by marine electronic shop in bunno and i have no issues at speed

 Got it all fixed today, took it for a quick run reading at 20knts! Will give it a real test on friday with any luck!