How to remount Lowrance Transducer

jsylvester08 · #1 02-06-2021, 08:48 AM

Happy February to those on the east coast. We are 1 month closer to boating season. I had a Lowrance Elite 7 installed and it’s been great. My problem is that if I get above a trolling speed it turns to a wash and doesn’t read any depth. Is this pretty common problem or was this just mounted wrong. I had it installed by a professional the first year and had the problem. Last year I tried to remount the transducer slightly lower on the hill but I get the same issue. Does anyone have any ideas or know a specific location I can mount it to read underway. I have an 86’ 20SF.

bumpdraft · #2 02-06-2021, 02:01 PM

I would have taken it back to the "professional " that installed it a couple years ago. A pic of the install might help here.

jsylvester08 · #3 02-10-2021, 08:57 PM

Thanks Bump- yeah I agree I should have taken it back but I get what I pay for and cut corners.
Boats in winter storage so will be a month or two before I have her back in the driveway for some pics but will post when I have them.

bumpdraft · #4 02-10-2021, 10:31 PM

My transducer has always been on the starboard side of the motor. Looking at the installation manual, it says that it needs to be 3feet away on port side. If counter rotating motor, the position is reversed. I never noticed anything like that in manual on my old Lowrance and I'll have to look at my Garmin one again.

SailorChlud · #5 02-21-2021, 02:45 PM

Does that model allow for shoot through the hull mounting? If so, that might help.

caper · #6 02-25-2021, 01:57 PM

Post some pics

nestorpr · #7 02-26-2021, 05:05 PM

I attached an installation manual here, it helped a lot when I was installing mine and it works great, hope it helps.

Fr. Frank · #8 03-01-2021, 05:23 PM

Quote:

Originally Posted by jsylvester08

Does anyone have any ideas or know a specific location I can mount it to read underway. I have an 86Â’ 20SF.

I believe I can help.

It depends on the type of transducer, first of all. Most "professionals" mount the transducer improperly, whether its a transom mount, thru-hull or in-hull 'ducer. That's most "professionals" are boat yard workers or mechanics or just riggers who've never taken the time to troubleshoot fish-finder problems.

The emitting surface needs to be completely below the hull of the boat Both Sides! Modern SideScan/Side-Vu/Side View transducers have an 84-87 degree emitter angle. That gives a total emitter transmission angle of 168-174 degrees. If the inboard side of your transducer has either the keel-line of your hull in the way OR the inboard side is above the hull bottom, its not going to work. In one case the hull is blocking part of the emission and in the other, it's emitting into the air whenever you're on plane or nearly so. No Bueno.

In the case of thru-hull transducers, you need a PAIR of transducers to take advantage of SideScan/Side-Vu/Side View technologies if you have a deep-V hull, or a proper kelson or keel.

In the case of transom-mounted 'ducers, it must be mounted away from any white-water or turbulence stream. That means you need the length of the transducer's aft protrusion in side clearance clearance from the path of any lifting corners, strakes, or chines. For SeaCrafts, this means the center planing surface is almost always the best place, and the center of the planing surface is the best. Also, you need to stay the equivalent of the radius of the prop away from the prop diameter to avoid the 'ducer introducing ventilation to your prop.

I have a Navico Simrad "Active Imaging 3in1" transducer on my 18' Superfisherman and I can hold steady SideScan imaging up to 27 knots in calm water. Above that speed I start to lose clarity. It's great for hunting for the lone rock pile to find snapper or grouper or AJ's.

I'll try to find a couple of old pictures of the proper mounting of a transducer.

Fr. Frank · #9 03-01-2021, 05:25 PM

Here's some pics of a good mount. Yes, it throws a lot of spray.

take a potter · #10 03-02-2021, 07:07 PM

One thing that I might add for transom mounts, is to put them on a mounting block 1" thick. Keep the bottom edge of the block above the bottom of the hull by 1". This allows the transducer to sit a little further behind the hull and therefore it can get in cleaner water as the water rises off the hull. Doing so helped me have a clear image up to about 30kts.