I'd like to put a fish finder on my aluminum fishing boat. I've had one many years ago and was unhappy with the transom mounted transducer.

I want to use a thru hull transducer. What model would you recommend? Hummingbird? Lowrance? Other?

This is a 14 ft jon boat so I don't need a huge unit. My budget is $500 or less.

Thanks in advance for any recommendations.

I am not an expert about brands, but through hull transducers are going to cost a lot more than transom mounts. Maybe look again at transom mounts?

Thru hull transducer are typically for composite hulls. Aluminum hulls are either drill thru mounts or requires specialized "shoot thru" transducers. This limits your options as these transducers are not usually offered or compatible with entry level graphs.

You didn't state the reasons why you did not want to go with a transom mount. If it is poor performance, it is usually due to improper mounting or poor location selection. Thru hull mounting will always reduces the sonar performance to some degree and eliminates some functions like water temperature.

I am familiar with Hummingbirds and Garmins. What features and capabilities are you looking for? What type of fishing or species you go after? Freshwater, saltwater or both?

Thru hull transducers are mounted by drilling a hole through the hull and mounting the transducer in the hole and sealing around it. In hull transducers are mounted on the top side of the hull and the signal is transmitted through the hull. I don't think you can use an in hull transducer on a metal hull. My suggestion is to use a good transom mount transducer. I have one on my boat that has sidescan and have used it with great success.

My reason for wanting a shoot thru transducer is this is a small boat and I sit near the back. A tiller handle steering. The transom location makes a disproportionate large and messy rooster tail.

There isn't much choice of where to mount it as the outboard takes up the middle area . I've had two transducers there and they both didn't work .

Perhaps I've miss installed them in the past. It has been several years and I don't remember every detail of how it should be done. Is it possible to mount it back on the transom and not all the way under the hull? C Won't the back of the transom block the signal forward?

This is for locating fresh water fish that are schooling in open water in a north Georgia reservoir (Blue Ridge) . The DNR has put 6000 trout in and I'd like to find them . Also Walleye like to inhabit open water.
I can catch bass by blindly beating the bank and structure I know of.

I don't need side looking capability or anything too fancy.

Thanks for the replies gents

I have an aluminum hull and I use a Humminbird Helix SI/DI. is a GPS and sounder combo. I have a transom mounted transducer.

The transducer on a regular fish finder only send the sound wave straight down. As the sound wave go deeper they spread out so in shallow water you are only getting a return over a small circle while in deeper water you will get a larger coverage.

A transom mounted transducer should not be mounted below level with the bottom of the hull. If the transducer is causing a rooster tail it is probably mounted too low. The hull will not block the signal because the signal is going down, not forward.

if you do go with a thru hull, make sure to mount it far enough aft so it stays in the water when you are on a plane and that it does not get hit by your trailer bunks.

Transom mounted transducers have improved over the years. I like and have several Hummingbird products. I have a small Hummingbird model 570 I believe it is, on the pontoon and it marks fish quite well at low to medium throttle. Go to You Tube college on mounting transducers on transoms and you will learn a lot.

Spinzone sez

quote:

A transom mounted transducer should not be mounted below level with the bottom of the hull

Ok. so there was my first mistake.

Thanks y'all

lastman.

I also have a pontoon. Where did you mount the transducer on yours? On the actual tube?

You can't put a thru hull transducer on your boat for anywhere near your budget including unit. I would suggest springing for a little more $$$ and get the Simrad go9 (9") with 3 in 1 active transducer. The 3 in 1 has side scan and etc and is chirp so will show a picture much better than the previous ones you're used to. You want to mount transducer on starboard side, I'd try epoxying one of those transom savers to your transom and then screwing the transducer to that.

Here is a Simrad go 9 remanufactured with 3 in 1 transducer (the transducer normally sells for almost $300 on it's own) for $629.

https://www.thehulltruth.com/s...go9-reman-629-a.html

West marine has the unit for $699 with a 83/200 transducer, but the 3 in 1 is better.

The go9 is one hell of a unit and a great chartplotter as well for the money.

Here is a 7" Lowrance with the 3 in 1 for $409.....
https://www.thegpsstore.com/GP...ority%20-%20Discount

Transom mounted transducers can be hard to properly tune to read at speed AND have little to no spray. Multiple companies make 'shields'/spray guards that help control the spray that is often the result of using a transom mounted transducer. The whole transducer shouldn't be below the bottom of the hull, but roughly half should. For proper reading at speed it should also be leveled based on how the boat sits in the water.

As others mentioned - for an aluminum boat the only 'through hull' options are exactly that. You drill a relatively large hole in the bottom of the boat and the transducer is mounted through that hole. It's not a popular option. With fiberglass boats you can get shoot through hull 2d transducers that are actually cheaper than the transom mount transducers (less hardware) and are generally used in conjunction with an imagining transducer (Side Imaging or Down Imaging).

Each brand will have it's strengths. Live imaging - Garmin. Mapping, side imaging and 360 imaging - Humminbird. 2d performance - Lowrance.

I primarily fish walleyes and muskies - I have 4 humminbird Helix graphs on my boat - a pair of 10s at the console (mapping/2d on one and Side Imaging on the other). I have a 12" and 10" at the bow for mega360, megalive, and mapping.

Mega Side imaging changed how I fish in all cases. You can drive around at 5mph and see if there are fish 100' out to each side. Finding structure is much easier as well - see something interesting - drop a way point on it and turn around to check it out. The technology is pretty amazing. Live imaging has the potential to do that, but I haven't spent enough time with it yet and the constant screwing around turning the pole takes away from the enjoyment of fishing for me. I am working on building my own turret to help with that (I don't want to spend $1500 on a turret).

Get the largest graph you can afford/are comfortable spending money on. The electronics setup I have is in excess of $12k, I'm a tech guy so I enjoy all of that 'stuff'. Do I need it? No - I could probably make due with 1 unit with mega side imaging/mapping, but having it all sure makes it more enjoyable.

Shoot me an email if you want to discuss more in depth - I'm happy to answer questions.

quote:

Originally posted by 9x18:
lastman.

I also have a pontoon. Where did you mount the transducer on yours? On the actual tube?

I'll be going down to the dock later I'll see if I can get a pic for ya.

If you've got a trolling motor up front, just mount it to that. And if you don't, you should put a trolling motor up front.

^^^And a big enough screen you can see while standing.

There are a few things to look into to find the ideal location for your transom mounted transducer. First where is the transom's waterline while not moving. Second, where is the transom's waterline when on plane moving at speed. Third the arc of your prop fully to port and fully to starboard. Also see if that arc is different when trimmed fully up and down.

The primary location objective is to find the smoothest flowing water absence of any turbulence. A few points I pulled from my install manuals for my graphs.
1. 15" minimum away from the prop
2. 1/32" to 1/16" below the bottom of the boat. Any lower, the transducer will cause its own rooster tail and back-flow cavitation at speed.
3. If your deadrisde angle is so steep to allow you to maintain the 1/32" to 1/16" mounting height, you will have to look into a transducer shroud.
4. Locate it behind a smooth bottom of the boat. Avoid rivet line, strakes, steps and ribs.
5. Mount the transducer on the down-stroke side of your prop.


As for the graphs, you want high resolution down imaging and side imaging. Your budget will not allow for the live imaging. You do want the best map available for your budget or make sure it is at least Navionics compatible.

I have Garmin Echomap on my kayak. A mix of Hummingbird Solix (for navigation) and Garmin Echomap (primarily for front facing sonar) on the center console boat. I fish stripers, hybrids and crappies for freshwater. And pretty much all game fish except sharks for saltwater.

I have a trolling motor but I want to use it at a little faster speed via my gas motor.

I want a big enough screen for sure. I like the Lowrance unit Jimmy linked but i"m thinking of the 9" vs. the 7".

I've watched some youtube videos and understand the transome mount much better now. I see some of my past errors and todays transducers are radically improved as well.

quote:

Originally posted by 9x18:
I have a trolling motor but I want to use it at a little faster speed via my gas motor.

I want a big enough screen for sure. I like the Lowrance unit Jimmy linked but i"m thinking of the 9" vs. the 7".

I've watched some youtube videos and understand the transome mount much better now. I see some of my past errors and todays transducers are radically improved as well.

Make sure to mount it on the starboard side of the transom......and follow the directions as far as height. Also go into the menu and change which frequency and chirp setting you like also the gain until you get the right picture for slow speed and fast speed.......read the manual as the new transducers do A LOT compared to the old ones.

You can never have too big of a screen.......can split it and do chartplotter on one side and fishfinder on the other and with a track line go back to exactly where you were before if you passed a good fishing spot.

My minkota trolling motor (on the front of the boat) has a built in transducer. It works beautifully. Maybe an option for you?