Month: August 2019

Improving my Simrad Sidescan – Part 3 (Re-mounting the Transducer)

Okay, so if you’ve been following along, I had identified a new location for my transducer – under the step and near the drain plug.  I REALLY didn’t want to drill more holes in the hull, especially since I wasn’t sure it was going to work in that location.  I did turn to Google to see if there were any posts about moving a side-scan transducer there, with marginal success.  Based on detaching the transducer from its current location and pulling some slack in my cable, I was able to eyeball the new location and see that everything seemed to be okay – the main concern being clearance of my lower unit when trimmed fully down and turned both ways. In that location it was clear that I would have an unobstructed view for a full 180 deg.  

Again, some Googling brought me to this site, that describes a way to mount Starboard (a.k.a HDPE) on a fiberglass hull.  HDPE does not like to stick to anything, usually.  I pretty much followed the instructions on the side to a “T” and had very good success with it.  Luckily I had some 3/4″ HDPE lying around already from other project(s).  If you need to get some HDPE, you can get it here.  Just in case the website link disappears in the future, I’ll list the steps below.  

Materials

  • 3/4″ white HDPE (a.k.a $tarboard)
  • 1/2″ drill bit or end mill
  • West System G-Flex 655 Epoxy
  • Blue painters tape
  • 80 grit sandpaper (or thereabouts)
  • Acetone or denatured alcohol
  • Propane torch

Cut the 3/4 HDPE to size for the places you want to make a mounting plate.  I chose to make 2 plates, one for the new location, and one to make a plate along the transom where transducers are usually mounted (and also to cover the old holes).  I figured while I’m at it, I might as well make a second plate “just in case” and covering the old holes was a second motivation.  

Once you have test-fit the HDPE block(s), drill 1/2″ +/- holes approx half-way through the thickness of the back part of the plate.  No special rule but put them randomly throughout the piece.  The link has some pics of what it should look like.  Unfortunately I didn’t take any pics of mine.  I then took a hand drill and 1/8″ drill bit and made short holes in the back of these holes angling to the side.  This is for the epoxy to grab onto.   The website says to make a lip underneath the holes.  Its really the same thing.

Next, use your sandpaper and rough up the back surface pretty good.  I also held the blocks on my transom and put painters tape around the perimeter of the desired location.  Then removed the block and sanded the gel coat so it was roughed up.  

Use your acetone and clean the gel coat and back of your block.  Get rid of any hanging pieces of plastic.

Using a propane torch, flame treat the back surface of the block.  Apparently this is the key to having the HDPE stick.  Pass the flame over the surface in overlapping passes at a rate of 2″ to 3″ per second.  It should not show any visible difference (ie. do not melt the surface – you can melt it if you go too slow).  The heat creates a chemical property change that aids the bonding.

Mix up the G-Flex (super easy to do, its roughly 50:50 mixture) and using a Popsicle stick or similar, fill the holes in the back of the block completely.  I also buttered the entire back of the block with a thin coat.  

For the next step, get your painters tape, paper towels and acetone ready.  Place the block in the desired location.  It will stick a little but will want to slide.  Using the painters tape, tape it thoroughly to keep it in place.  Don’t worry if its not perfect.

Blocks set in place and taped up while the epoxy sets

Wait about an hour and come back and remove the tape.  Make slight adjustments in the location.  Wet a paper towel with acetone and clean up excess epoxy now.  Re-tape to hold the block in place.  Give it a good 24 hrs to set.  Should be a very solid hold now.

With the blocks being set I went ahead and placed the transducer with my motor trimmed as far down as it would go in the driveway making sure it cleared with the wheel turned all the way to the left.  This was a goof – as described below (I do a lot of dumass things)! 

HDPE blocks placed and transducer set in new location. Wire secured with temporary double-sticky anchors

Took it out to trial it, and images were great, both left and right.  I did a check when trimming the motor ALL the way down and turning the wheel and quickly noticed that it would hit the transducer IF trimmed all the way down.  Something that I really never do (lowest I go is 40%) but Murphy’s Law says “if it can go wrong, it will go wrong”.  When I got back home, I lowered my trailer jack all the way down so that I could trim the motor to the locks and turn the wheel.  Luckily I was able to shift the transducer about 3/4″ right and avoid an interference.  (AH, the benefit of having a block – no new holes in the transom!)

After shifting the transducer to the right. Note the fish line used to align it to the boat hull

 

Clearance is very tight when trimmed all the way down and the wheel turned all the way left. But – – no possibility of interference in this location

After all this, the only thing I did was replace the temporary cable ties with smaller profile ties secured with a tiny bit of G-Flex.  Again – no holes in transom. 

I’ll just need to be careful of having the transom get beached (I do this anyway) but it is a little more vulnerable in its current location even though its above the bottom of the hull.  For me, having the advantage of a full view of my side-scan and getting everything out of it is worth the additional risk of it in its new location.  My last post on this subject will show some of the images I’m able to get now.  Stay tuned!

Improving my Simrad Sidescan – Part 2 (Initial Results and Issues)

So, where I left off on my last post, I had purchased a replacement transducer and installed it in the old mounting bracket. 

So, upon inspecting the new Simrad / Lowrance ActiveImaging 3 in 1 transducer, the first thing that was apparent was that it is significantly deeper than the StructureScanHD.  In other words, it sticks down farther from the mounting bracket.  When I mounted the new transducer I used the old bracket and this made the new unit stick down just a little below the bottom of the hull, maybe 1/2″.  In my haste to see what difference it would make, I took it out for a trial.  Turns out, that was a bad idea.  The force of the water hitting the transducer was enough to bend the metal bracket and twist it.  But, I was able to get some images to show that the new transducer is in fact a big improvement.

New transducer mounted on the old bracket. Note that it got bent after a sea trial!

Some initial screen shots after driving around at Edisto during a short family vacation:

First look: Suspended schools of menhaden.  Menhaden were flicking on the surface nearby, but not in this location.

 

First look: Dock pilings with potholes carved out around the bases.  Note the crisp shadows from the pilings.

 

Ah! Large redfish under a dock. Note the floater signature (thin vertical lines)

If you look closely at the above plots there are a few problems still…  

First, if you look at the center of the image.  This is where the transducer is.  Note that on the right you see a clear black zone, but on the left you see yellow lines where the water should be.  This is interference from the motor’s lower unit.  You could trim the motor up out of the way whenever you need sidescan but really, who’s gonna do that?  Not me.  The other very significant result of the lower unit interference is that the left side of the plot is almost useless.  You see almost no detail on that side, if you look at all the above plots.

It’s now clear that the transducer should be moved, both to mount it safely above the bottom of the hull for one, and also to hopefully allow a full 180 deg unobstructed view.  Looking around at my options, it appeared I could mount it near the center of the hull next to the drain plug and meet both requirements.  

New desired mounting location: Under the “step” and near the drain plug.

But, I wasn’t sure where exactly to mount it – and no one wants to drill more holes in their hull.  The next post will discuss how I solved these problems, and where I am at today.

A side note:  Ben made a point to say he purposely installs the transducer himself to make sure its done right.  I, like most people I guess, had the factory/dealership install it.  I’m honestly not sure who installed it but in hindsight, it was originally installed in a bad location for its purpose.  I would recommend anyone who reads this and is purchasing a new boat with side scan to either ask where its going to be mounted or do it yourself.  That is, if you want to get the most out of your unit! 

I’ll have the third part of this series updated in a few days…

Improving my Simrad Sidescan – Part 1 (Background)

This will be the first in a several part series of blog posts documenting my journey to improving my side-scan sonar, based on what I learned from Capt Ben Powers at our Eye Strike Artificial Army Seminar on the subject of Setup and Interpretation of Sonar.  If you missed it, you can watch it in its entirety here (Note that there are 4 separate videos covering the seminar).  

Background

So, I took delivery of my Sportsman Masters 207 in June of 2018.  I knew I wanted side scan technology so I just asked for a side-scan transducer.  What I got was a Simrad StructureScanHD transducer.  It was mounted on the side in the general location where transducers typically are, up near the right trim tab.  I could see all kinds of cool stuff with it and was generally pleased with it.  I knew I had a pretty good understanding of what I was looking at, but really felt Iike there was a lot more to it than I was understanding.  

Original location of my Simrad StructureScanHD transducer from the factory

With this in mind, and having had many conversations with friends and customers on the subject, I felt like this was a great first seminar where we could go in depth on the subject and learn a lot from it.  Having gotten to know Ben Powers through the course of business and hearing about what he was seeing on his side-scan, he became the natural choice to deliver our seminar.  

Ahead of our seminar, I didn’t want it to seem like an advertisement for a particular brand of sonar, so we discussed bringing my boat down to Folly and getting some comparison images between our units.  He is running a Humminbird Solix.  Honestly, I was feeling like I would get very similar results to his….Wrong!  

The difference in images was very significant.  His were crisp and high contrast.  Mine were blurry and low contrast.  He could identify individual fish under a dock, I could hardly see anything of interest.  

Simrad StructureScanHD (Left) and Humminbird Solix (Right) passing by the same structure. Not so great for me!

If you know me, you know I couldn’t let this rest!  I figured that competition being what it is, that Simrad probably had an improved sonar available to compete with Humminbird.  I did some googling and had a few interactions on social media and discovered that, yes, this was true.  There is a better transducer called ActiveImaging 2 in 1 or (3 in 1) available and that it was relatively inexpensive (under $300) and a bolt-on upgrade.  You simply mount the new one, pull the old transducer cable and route the new one and simply plug into your NSS-EVO3 unit.  It automagically recognizes the new unit.  

I went ahead and placed an order for the new unit.  I got the 3 in 1 because it also allows Med and High Chirp echo which my current thru-hull transducer does not have.  

Sportsman does a good job allowing cable runs to the console and pre-inserted pull cords, plus, of course the all-access bilge which is A-MAZING.  I am able to fold my entire 6 ft tall body inside the bilge to work on stuff.  So, once the transducer came in, pulling and routing the transducer cables was relatively easy with a couple hours and a little bit (OK, a lot!) of sweating.   

Before I got a chance to try the new transducer, we had the seminar and I learned that how and where the transducer is mounted is almost as important as anything.  

The next posts will discuss initial results, how I repositioned my transducer, and what results I am getting now.

Stay tuned and I hope someone finds all this of interest!