Need help with transducer placement-Sea Ray 175

[acs2653]

Hey guys. I'm installing a depth gauge in my boat and need help with transducer placement and how to run the transducer wire up into the transom. I have a hull saver but I am unsure where to place it in my boat. The transducer is a Lowrance skimmer. Here is a picture of my transom. Need help with where to mount the hull saver so it won't interfere with trailering and where to make the hole to run the wire. Also if anyone has any info on what hardware to get to make it look professional, please let me know. Thanks

 

[TyeeMan]

If you have the manual, by all means go by that. They should have detailed instructions as to where to mount the transducer.

That said, very likely they will want you to mount the transducer at least a foot away from the out drive in order to reduce "noise" and turbulence. I see you have a hull streak just to the left of your trailer bunk. You will want to mount the transducer to the right of the streak possibly right in line with your trailer bunk providing the bunk will never stick out proud of the transom.

If by hull saver you mean the 4" X 8" or so piece of delrin plastic on which transducers get mounted to? You will want to mount that 1/4" to 1/2" higher than the bottom of the boat. Should say on packaging. They probably give you two stainless steel screws to mount with. I typically put a nice few beads of clear silicone on side that will mount to the boat, , just to make it a little more sturdy.

When you purchase your hardware to mount the actual transducer, make sure the screws will not be longer than the hull saver is thick. So if the hull save is 3/4 inch thick, don't buy one inch long screws. A 3/4" screw with a washer will be just the right length. Just in case you didn't know, screw length is measured from the bottom side of the head.

As for hardware, always, always use stainless steel. And use a lot of well placed silicone sealer for whatever holes are drilled into the transom.

I would really hate to drill a big ole hole through that fiber glass in order to get the plug through. What I've done on previous, and my current boat is purchase some adhesive backed zip tie mounts. They're usually available in clear and black and come in 1/2" square and 1" square sizes. My boat is dark green so I used the 1/2 inch square black and small 4 inch long black zip ties. Find a good cable rout up from the transducer, up and over the transom of the boat. Place the adhesive backed zip tie mounts 8" to 10" apart. It's a little more obtrusive if you will, but you won't be drilling a big hole in the back of the boat.
If you make a good cable rout into the boat, it may not be very noticeable at all.

I'd take picture of my boat but it's in the shop until tomorrow.

 

[Old Ironmaker]

Use 3M 4800 to seal the Delrin plastic, if you never want the Delrin to come off use 3M 5500. And follow TyeeMan's well thought out instructions. I did drill through the transom as high as possible to get wire through, and sealed with 3M 4800, then a nice stainless or chrome wire cover to cover the hole you can get at a local Marine supply.

 

[acs2653]

Use 3M 4800 to seal the Delrin plastic, if you never want the Delrin to come off use 3M 5500. And follow TyeeMan's well thought out instructions. I did drill through the transom as high as possible to get wire through, and sealed with 3M 4800, then a nice stainless or chrome wire cover to cover the hole you can get at a local Marine supply.

So where should I run the wire through the transom at? Above the bumper in the white area or as high as popossible in the yellow?

 

[TyeeMan]

No Title

I tried to upload a picture of my boat so I hope it works. My boat is an IO as well, I have little jump seats on each side of the engine housing. This picture is prior to me buying the boat but it will do for illustration purposes. If you can blow up the picture, look at the old white haired guy, , nobody I know. See the watch band on his left hand, there is a black wire that runs along the tan part of the boat, that's the transducer wire. What the previous owner did was run the wire past the chrome vent and then into the boat right next to the back rest of the jump seat.

When I got the boat I installed new electronics. I use the same general wire path, but to clean it up a bit I removed the chrome vent and made a U shaped cut out just big enough for the wire at the base of the vent. I dropped wire into vent hole, replaced the chrome vent so the wire was captured in my little cut out and continued to run the wire to the helm. Looks quite nice if I say so myself, , and no drilled holes. :thumb:

 

[acs2653]

I tried to upload a picture of my boat so I hope it works. My boat is an IO as well, I have little jump seats on each side of the engine housing. This picture is prior to me buying the boat but it will do for illustration purposes. If you can blow up the picture, look at the old white haired guy, , nobody I know. See the watch band on his left hand, there is a black wire that runs along the tan part of the boat, that's the transducer wire. What the previous owner did was run the wire past the chrome vent and then into the boat right next to the back rest of the jump seat.

When I got the boat I installed new electronics. I use the same general wire path, but to clean it up a bit I removed the chrome vent and made a U shaped cut out just big enough for the wire at the base of the vent. I dropped wire into vent hole, replaced the chrome vent so the wire was captured in my little cut out and continued to run the wire to the helm. Looks quite nice if I say so myself, , and no drilled holes. :thumb:

That does look slick. My issue would be the swim platform on the back of mine. I don't want to put it there since someone could catch a toe on it.

 

[TyeeMan]

Yep I understand. I have a swim platform as well but 99% of the time I will be the only one using it so I guess I have the awareness of the transducer.
Now that I think of it, having used the swim platform a handful of times with my new transducer, I never ran into any problems. My transducer is a Humminbird skimmer and probably sticks out all of 6 inches past the transom.

 

[acs2653]

Yep I understand. I have a swim platform as well but 99% of the time I will be the only one using it so I guess I have the awareness of the transducer.
Now that I think of it, having used the swim platform a handful of times with my new transducer, I never ran into any problems. My transducer is a Humminbird skimmer and probably sticks out all of 6 inches past the transom.

So where should I run the wire into the transom at? I plan to mount the transducer just to the right of the bumper guide on the transom (only place that will really accommodate the HullSaver). I just cant figure out where the water line sits back there. I just want to make sure that my wire running into the boat is above the water line.

 

[Texasmark]

I liked mine inside the boat where it can't be seen, can't get damaged, and turbulence is reduced for better signal to noise ratio. I use a bubble less 2 part epoxy if available (bubbles attenuate the signal.....sound travels through a solid 10x or so better than air) and epoxy it to the bottom of the hull as near to center and close to the transom as the hull design will permit. It is most accurate if pointed straight down, if you have a lot of dead rise at the stern, make a shelf out of solid epoxy to set it level.

 

[TyeeMan]

Looking at your picture, at the top right of the picture there are two stickers on the boat with something between the pictures. What is that? To be less obtrusive you could you enter the hull an inch or two below whatever that thing is?
As for water line, I'll bet it's about 1/2 up or less on the yellow. Certainly will be well below the rub strip.

Texasmark has a great idea too. I was going to throw that out there but didn't. It's called shoot through the hull. I've never done it, , never had a glass boat, , but it's definitely an option. Then you don't have to drill any holes into that nice glass.

I think you might have to get a different transducer though, I don't think you can shoot through the hull with a skimmer type transducer. Not a 100% sure on that. . .

 

[Texasmark]

Texasmark has a great idea too. I was going to throw that out there but didn't. It's called shoot through the hull. I've never done it, , never had a glass boat, , but it's definitely an option. Then you don't have to drill any holes into that nice glass.

I think you might have to get a different transducer though, I don't think you can shoot through the hull with a skimmer type transducer. Not a 100% sure on that. . .

You are working with sound waves normally 50 kHz (50,000 vibrations per second frequency) and 200kHz. Depends on the unit and cost what you have. 200 is the most popular for single frequency last time I bought one. Sound travels through solids better than air due to the molecular weight difference of the two substances. Therefore you don't want any air (if you can help it) between your transducer and the hull and the hull needs to be solid glass or metal where you mount it....none of this balsa wood sandwich glass/balsa/glass. I quit mounting outboard back in the 70's when the kids were at the best age where the family could really enjoy a Sunday afternoons skiing. They'd get knocked off, or loading on the trailer in a cross wind, or Bass fishing in standing and fallen timber reasons.

I never used anything but the type that normally mounts to a bracket on the transom. The piezo crystal is hard molded to that plastic module so you can hard glue it to your hard glass or alum. hull and protect it.

 

[Old Ironmaker]

So where should I run the wire through the transom at? Above the bumper in the white area or as high as popossible in the yellow?

First off it's 3M 4200 or 3M 5200 my bad. I can't see what is on the inside of the transom, is there a splash well or is closed? Mine is aluminium and splash wells are fairly all the same in my experience. I wanted to look at my boat to see exactly where I ran mine. It is just below the top on the transom. Your would be just below the rub rail in the yellow area I would think, again depending what there is on the inside of the transom. I filled the wire cap with 4200.

Mounting a transducer is always best shooting through the hull as Texasmark said for more than 1 reason. I would have but can hardly get my arm in the bilge porthole let alone work with one hand and blind. The day I have to replace the bilge pump is the day I tow it to the marine mechanic and pay the guy.

 

[dingbat]

Depth reading, in hull mount is fine.

Fishing, not so much.
While sound waves transmit thru "solid" Fiberglas very well, the glass causes a frequency shift in the signal. The effect correlates to hull thickness on a non linear curve so there is no way to compensate or offset the effect.

Yes, you have surface clutter on a transom mount to deal with but at least the full signal spectrum is available for analyst. I know that school of minnows I'm looking for isn't "filtered" out by the hull.

 

[Texasmark]

Depth reading, in hull mount is fine.

Fishing, not so much.
While sound waves transmit thru "solid" Fiberglas very well, the glass causes a frequency shift in the signal. The effect correlates to hull thickness on a non linear curve so there is no way to compensate or offset the effect.

Yes, you have surface clutter on a transom mount to deal with but at least the full signal spectrum is available for analyst. I know that school of minnows I'm looking for isn't "filtered" out by the hull.

I do agree that any medium can be a filtering agent of some sort. Testing would be the only way to tell. I remember one outing on Lake Palestine, TX, I was sitting in the front seat and had a ducer epoxied to the hull right under me, working a long bank in about 10 feet of water. I had minnows and would watch my ducer and when a spot would shot up, I'd check the depth, figure my line length and over the side would go the minnow. Worked like a charm and probably one of my best fishing trips for just having fun being able to do what I said and it work.

What I have recommended in the past on filtering and/or attenuation is to get in water the depth you boat most often. Drop the ducer over the transom and take data. Put the ducer in a gallon zip lock bag full of water or just sit it in a pool of water in the bottom where you are going to locate your ducer. Recheck your data. Problem solved.