I was going to hijack WPT Jeff's thread, but decided not to.

What is everyones oppinon of Transom Mount Transducer vs. Thru-Hull, where its mounted in the bilge and sounds through the hull?

Thanks

Zac

I have an Airmar (P79 I think) shoot thru transducer and it works great. I get readings at WOT, don't have to worry about a ducer hanging off the back or getting growth on it. I can't use speed or temp obviously, but don't need to.
Bill

Zacs,

I prefer thru hull. Mainly for I hate hanging stuff off the back of the boat to get fouled when I'm fighting my trophy. Whenever that is......and I have an inboard.

If you already have an outboard what's one more little thing off the back.

Zacs-

I have a transom mounted 'ducer on my SeaCraft and it works really good when at a troll or a bit higher, say 7kts. Anything higher and I lose bottom and get zero fish locating abilities.

But, in the real world, I only need it when I arrive at the spot where I am going to fish. If I want to check out a spot, I am sure going to come off plane to have a look-see. I wouldn't make a decison on a spot at cruising speed!

Don't know much about the shoot through type, but by all accounts, those that use them seem to like them.

But I agree with Jon, the best readings are with a thru hull transducer. If you can do it yourself or can get someone to do it for you that's the way to go. Make sure you know what the heck your doing tho because it takes major 'nads to cut a hole in your hull and it really should be done right the first time!:cool:

it takes major 'nads to cut a hole in your hull and it really should be done right the first time!

someone please correct me if I'm wrong, but I thought you epoxied the thru-hull in the blige where it would shoot straight through the glass. There is no way I am going to cut a hole in my hull under the water line. I do not have that kind of "nads" as hooper puts it.

Thanks for everyones help.

Zc

Zacs,
What you're talking about is often called an In hull transducer, a through hull is exactly that, it is installed though the hull, and is IMHO the best installation you can get, but you do have to cut a hole in the bottom of the boat.

Thanks for the clarification MM. So, any comments on the kind that shoots through the glass from anyone?
Thanks
Zac

Zac - Unless you have a cored hull, go with the P79 or similar.I have a Seacraft also and get great readings at 40 mph. Hooper may be right in most cases, but when you're haulin ass to your spot, it doesn't hurt to see a huge pod show up in 30 feet of water either. Last time I checked I still had nads, but a thru - hull concerns me if I should hit something.
A shoot thru is as easy to install as a transom mount. All you do is epoxy or 5200 this little cup to bottom in the bilge, and pop your ducer in. At least with my GArmin unit, this setup works well.

Bill

:) I also have a transom mount and like Hooper after about 20kts. my transducer goes bonkers, a lot of static!!! My friend had one of them shoot throughs and loves it!!! A friend of mine is procuring one for me boat!!!!;) :cool:

Thru-hull is the way to go but if you're trailering make sure you will not screw it up putting on & off the trailer.

Shoot-thru is second best, speak with the mfg of your boat & they can tell you if it will work with your hull & if so, where to mount it. I went with the Airmar one that adjusts for angle of the mounting surface & you fill it up with mineral oil, can't remember model # + I never lose my reading at any speed.

Transom mount - last resprt. I've seen too many kick loose + several break off.

Good luck.

Works fine for my skiff... (transom that is)
We have a transom mount for the r/v and it works ok, but over 15kts, forget it... then again over 15kts I dont care anyways...
B

Interesting stuff....

Can you tell me how you have your shoot thru mounted in the bilge? Is it off center with some sort of leveling device? Or is it mounted on center in the bottom of the bilge?

Hmmm, maybe I will have to rethink my 'ducer...

You have peaked my interest!!!:D

God, I hate December...:(

I agree with hoops. Both in that this is interesting stuff and that I hate december.

By the way, old outboard has been removed. Now for on to re-building the transom.

Keep any info coming on the transducers. I would like to gather as many oppinions as possible. Then I gotta make my mind up on which unit to buy. I am debating between the Garmin 188C and the 178C. 188C looks nicer, but costs about $400 more.

-Zac

Originally posted by Hooper
Interesting stuff....

Can you tell me how you have your shoot thru mounted in the bilge? Is it off center with some sort of leveling device? Or is it mounted on center in the bottom of the bilge?

Hmmm, maybe I will have to rethink my 'ducer...
(

Airmar P79

Transducer Options
Airmar (603/673-9570; airmar.com) makes transducers with unique mounting systems specifically designed for shoot-through installations. A round or rectangular well (depending on the transducer model) with an open bottom is glued around its bottom edge to the hull. The transducer is then placed inside, the well is filled with mineral or castor oil and capped on top. The assembly’s design compensates for hull deadrise and keeps the transducer aimed straight down. Flexible adhesives can be used because the transducer doesn’t shoot through the glue, but operates through the oil, hull and water below.

Hey Hoop,
Like roop said. The P79 is like an open bottom cup and the bottom is cut at an angle. It even has numbers molded into it cooresponding to your boats deadrise. You twist it til your deadrise is pointing forward which makes the ducer point straight down. Fill it with mineral oil, screw on the ducer and your ready to go.
I don't know how this pic will come out , but lets see:
.
http://www.airmar.com/Product_Catalog/marine_catalog/inhull/img/minpics/P79.jpg
.
Bill

Pretty great stuff, I guess I'll have to get one for next season....and by the way, my wife is now pissed at you guys! :laughs:

"That boat again!!!!" :af: she says!

I am lucky that she enjoys being on the water and usually getting more and bigger fish than I do!

I found a 50/200 online for about 75 bucks, does that sound right?

I have a in hull shoot thru, I put a big puddle of marine silicone and pushed the transducer in it and made sure it's level side to side front to back no problems what so ever
later link sr.:cool:

Where in the bilge is best to stick it? Bow, stern, midship? Anywhere? The reason I ask is beacuse access to my bilge is very very limited. (like one little 8 inch round hole in the stern)
Thanks, you guys are really helping me a lot with this one.
_Z_

I have a Garmin 160, and have the transom mount and I see bottom even up to 35 mph! Never had a problem

Don't put the transom mount too close to the trim tabs...

Zacs,
You can stick it anywhere that is always in water, in other words don't go to far forward where the hull might be getting some air when you accelerate or in a chop. The rear 1/3 of the boat is usually o.k.
The other thing is, don't position it behind any obstruction like a raw water pickup for example.

Bill

when you mount in hull ,first you must sand and clean the area w/ acetone let dry then lightly scuff the transducer even with a scotchbrite. Then a puddle of marine silicone make sure there are no bubbles in puddle ,go slow and keep nozzle in puddle that way you'll be sure there are no bubbles.
I made the puddle about 3/4" wider than the transducer and about 1" thick and pushed the transducer in made sure the complete bottom of the transducer was in silicone(sunk in 1/8 ")
level front to back and side to side.
there is another forum regaurding this topic the plus and minus
of in hull mounting PM me and I'll give you the info how to get it.
Good luck LINK SR.:cool:

Not that anyone cares, but I went with the transom mount. I also decided on the Garmin 188C. Thanks everyone for your help.

_ZAC_

Before you mount the transducer, take the boat out to find the right spot on the transom. While someone drives, look over the transom and note where the water comes out clean (and not in the path of the prop). Midpoint of the clean area is generally the best place for the 'ducer.

Thanks for the advice

Zacs, another idea if you are going to transom mount is to put a strip of starboard on the transom. Either mount it with just adhesive like 5200, or with a couple screws sealed well with 5200. A lot of people will do this so if you find you want to relocate the ducer to get better results, you don't have to keep drilling holes in the transom until you find your sweet spot.

Originally posted by Billybob
Zacs, another idea if you are going to transom mount is to put a strip of starboard on the transom. Either mount it with just adhesive like 5200, or with a couple screws sealed well with 5200. A lot of people will do this so if you find you want to relocate the ducer to get better results, you don't have to keep drilling holes in the transom until you find your sweet spot.

How are you going to get the starboard off if you put it on with 5200? You'll take half the transom off trying to remove it!

Originally posted by MakoMike
How are you going to get the starboard off if you put it on with 5200? You'll take half the transom off trying to remove it!

Easy, starboard and seaboard does not adhere well to 5200. Which is why it should not be used as the sole method of attaching to the transom. He needs to use screws to hold the starboard and the transducer if he goes this route.

I see. How difficult is it to find this "sweet spot?"

Not hard if you do the test ride and see definite clean water.