Thru Hull vs In Hull Transducers

I am far from an electronics expert but I have had crappy luck with depthfinder transducers mounted on the inside of the hull. I assume that is what you are asking about. I am not an avid fisherman so I was only using modern depthfinder tech. Don’t know if there are some other hull mount transducers that do well with cutting edge fish finders.

Can you hear me?
Can you hear me?

Oh wait..
Let me talk to you outside of the hull.

Can you hear me now??

If you are into fishing or really need to read the bottom for anchoring, Then you will want a thru hull mounted transducer.
If you are pushing just a digital depth sounder, An in hull puck may work.

Some folk get lucky with their inside mounted ducer, some folks crash & burn and swear never to be so cheap again.

IMO, do it rite the first try, Get the best thru hull ducer your checkbook can afford.

Reuse an existing hole then.
Better yet? What ducers do you have installed already?
Most ducers are mfg'd by Airmar corp. You may already have a good ducer installed.
Look for a tag close to the ducer and cross it back to the Airmar standard.

Again, depends on what new gear.
Just a pinger, 200htz has been a standard since Moses.
You may already have one installed.

The latest gizmos, Chirp, Side view and more are later designs. Usually made by Airmar also for the different mfg's.
If not compatible, there is an existing hole in your hull.

Don't kick analog radars to bad. I'm still using a 15+ year old 10KW x 6' pedestal unit.
AND, spares in the shop.

The In Hull ducer is for boats that have a high cruise speed and want the power of 2kw or 3kw transducer to shoot deep. I had a R599LM on my 40 Cabo and it worked great. I wouldn't want a 3kw fairing block on a 40ft hull that cruises at 30 knots. Another consideration is mounting location options. You also need a hull that has very high quality glass layup with no air bubbles.
On a Ocean Yacht I would mount a 1kw powered thru hull on a fairing block. Years ago I had a 40 Ocean SS with a Airmar B260. Worked fantastic.
All things being considered on a boat with space near center line for transducer with accessibility I would go thru hull over in hull. I would also use a fairing block. On larger boats the low profile transducers dont work well beyond hull speed.

A 1kw size fairing block on a 22knots boat is no problem.

A 3kw fairing block is much large and if not mounted on centerline can have consequences at 35 knots.

Go to Airmar and poke around a bit. Look at specs. Do some searches. What expectations a person has that just wants to mark bottom vs a fisherman who wants to see separated arches at 800ft are very different as well.

Just posting my experience after installing about 8 transducers the past decade.

I put one of those thru-hull ducers in my 14' RIB I carry on the bow and it has been a PITA. It has to sit with liquid between it and the hull and when it leaks out of the enclosure to hold it the dang thing won't work. Fixed it again last season and we'll see how long it works. I don't know if they all work the same way or if just the model I ended up with.

I have a Airmar P79-BL for my Simrad unit. They make them for most mfgs. out there. It's the screw in end / cable that must fit into your unit. That varies. It costs around $200. Mine has been great for three years now. Very accurate and no jumping around. Remember , our hulls are thin! Easy for it to shoot through.
Just follow the installation instruction to the letter. It will work great.

I removed two of the original thru-hull transducers that went to old out dated electronics.
I plugged the holes.
AND my boat is not a fishing boat. All I want is the depth keep in mind.

Yes you have to fill them with liquid. I used pink antifreeze so it wont freeze and break in the winter. You shouldn't use plain water. Works fine in my big boat. Not a lot of slamming around like a speed boat.

I do not use oil.
Just “pink” winterizing antifreeze.
No big mess.
Mine is easy to get to so that helps .
Clean area good with acetone, seal down outer tube with fast cure 5200. Let dry.
Fill about half way with antifreeze and set the round transducer in. Let the excess antifreeze spill out as you push it down . install the screws to hold down and seal the transducer to the outer base, and you’re done.
Three years , good so far.

take the liquid out, and epoxy it in with clear epoxy, set it directly in the epoxy, it will shoot right through no problem