Thru-Hull Transducers

[Tom.B]

I don't want to hijack the other thread... So here is a new one

We are hauling out in two weeks to do a few little projects. One I am considering is to install a thru-hull transducer to support a future depth sounder/MFD next year. <- I hope

What should I look for? What should I avoid? Any and all tips would be GREAT!

Thanks for all the help I get here!

*edit* How much dead rise should I look for?
*editv2* Will most T-ducers work with most/all brands of sounders?

Like this one: http://www.westmarine.com/webapp/wc...toreNum=10103&subdeptNum=10257&classNum=11062


-- Edited by GonzoF1 on Friday 5th of November 2010 06:32:13 AM

-- Edited by GonzoF1 on Friday 5th of November 2010 06:34:21 AM

-- Edited by GonzoF1 on Friday 5th of November 2010 06:36:19 AM

 

[Larry M]

I would wait to pick out*your transducer until you have decided which fish finder you want.* In August we installed 2 transducers.* One was for an older Furuno FCV-667 color video sounder in the pilot hose.* Here we added speed and temperature.* We also installed a new Lowrance HDS-5X high-def broad band finder on the flybridge and installed a triducer.* It took a while to determine which transducer to buy for our application.* For the most part transducers are not interchangeable because of the connectors and specific application.* Airmar is the transducer manufacturer for Furuno, Lowance, Raymarine, Garmin, Simrad and Northstar (I'm probably left out a few).* Here's the link for Airmar.* They*also have a compatibility menu and it gets pretty involved.*<a href="http://www.airmartechnology.com/airmar2005/ex20/RMProducts/DrillDown.asp?Type=FF">

http://www.airmartechnology.com/airmar2005/ex20/RMProducts/DrillDown.asp?Type=FF</a>

Good luck,

Larry/Lena
Hobo KK42
La Cruz, Nayarit, MX

 

[Tom.B]

Thanks Larry... I just called Airmar. He agreed with you and says it's smarter to wait. Oh well... Next year, I guess. Or I'll just rig an in-hull until the next haul-out.

 

[Nomad Willy]

Gonzo,
You could put a transom mount type on your swimstep bracket or whatever back there.
Had one on my old Albin and it was fine*** ...a Hummingbird. Get a fish finder type and
then when you get your high end super sounder later you've got two*** ...run one shallow and run one deep....or?

 

[Tom.B]

Wouldn't you want to know how deep it is BEFORE the STERN of the boat get to the shallow stuff? Call me crazy, but I would want the info before 35' of boat is on the bottom.

Besides, isn't it too "bubbly" back there for a transducer?

 

[Marin]

I doubt that you're going to be approaching a slope to shallow water that's so steep that the depth recorder will be indicating plenty of water under the stern when you have nothing under the bow. That can happen with a rock or reef, of course, but if you're not looking at the charts and paying real close attention to where you are and where you're going*when you're in shallow water or water with rocks and reefs*a depth sounder isn't going to help you no matter where it's mounted

Yes, the turbulence off the back of a boat can mess up the transmission and reception of depth signals. When we bought our Arima trailer boat way back when we installed a transom-mounted transducer which is the typical installation for this type of boat. Before installing it we took the boat to a lake and ran around at speed to determine where the clean water was coming off the back (it's a planing boat). That's where we mounted the transducer and it's worked just great all these years since.

Given the luck people have apparently had with shoot-through-the-hull transducers I would suspect that for larger boats like the kinds we all have, this would be preferable to a transom-mounted transducer unless the water coming off the back of the boat comes off really cleanly.

Our GB has a conventional through-hull mount for the transducer and this is what I personally prefer. But from the posts here and other places, it sounds like shoot-through-the-hull transducers can work fine, too.


-- Edited by Marin on Friday 5th of November 2010 10:48:54 PM

 

[Sailor of Fortune]

The difference between having the depth info at the bow as opposed to the stern is irrelevant
in my experience. Do you really think you would be able to stop and reverse your boats momentum in 35 feet or less?
If I am in a spot that requires that type of maneuver, I probably shouldn't be there in the first place.
Good return from my transducer/depth finder is my primary consideration rather than fore/aft
placement IMHO.

 

[Tom.B]

Good points guys. Didn't really think of those. THANKS!

I am really paranoid about going aground my first time. For some reason, I actually DO think the bottom will suddenly jump up to two feet. I spent a lot of time aground in our 16' ski boat (at 15mph) as a kid and learned to respect the unpredictable bottom of the Bogue Sound. But I'm slowly getting used to the reality that the bottom, especially around the NC coast, just doesn't do that. On top of that, this boat really needs to stay in marked channels anyway.

I'll take your advice and go transom-mount (or in-the-hull) until next year.

Tom-

 

[koliver]

Even your transom mount can be epoxied to the inside of the hull where it will perform very well. I did this with my RIB this year and have been very happy with the performance of the sounder. I did this because the dinghy is the one boat that will be going into potential grounding situations and I dont want to damage the transducer. I dried out a spot in the hull, near the stern, where the planing hull will still always be in the water and pushed the transducer into a mound of thickened epoxy. Works well.

In my trawler, I attached a transom mount transducer to the inside of a length of 4" ABS pipe, cut the pipe to the deadrise angle of the hull and epoxied the pipe in place. A little light weight oil ( I had lots for the hydraulic steering, so that is what I used) and good returns.

 

[Sailor of Fortune]

"there are 2 types of boaters- those that have been aground and those that are going to go aground"

If you havn't been aground -you havn't been boating long enough!

This is the reality of the cruising boater.

Once while off loading lobster traps (at high tide -town dock), the capt sent me to the bow because
we were hung up. Somebody had drove a stolen Nissan 300zx off the dock the night before. We were "aground" on the back of the car.

Many times in the ICW you can go aground in the channel, especially if you stay close to single pile ATON near the bends.

 

[Larry M]

Here's Airmar's link for "inside" or "in"*the hull transducers.** The installation instructions give some good guidance on locations and testing.

http://airmartechnology.com/airmar2005/ex20/RMProducts/ElectCat.asp?ProdID=52&Man=All&PageNo=99

or

http://tinyurl.com/27c5pcm


Larry/Lena
Hobo KK42
La Cruz, Nayarit, MX

 

[Tom.B]

Sailor of Fortune wrote:

"there are 2 types of boaters- those that have been aground and those that are going to go aground"

If you havn't been aground -you havn't been boating long enough!

This is the reality of the cruising boater.

Yeah, yeah, yeah... Heard all this before. I think the saying goes, "If you haven't been aground, you haven't been around."

Still, I'm doing everything I can to prevent it and to be the guy that you guys know who has owned a boat for a very long time and never been aground.

(jinxed myself I'm sure)

 

[FF]

I'm doing everything I can to prevent it

The world has been mapped , better and better as time goes by.

Today to NOT run aground all you need is your position.

Of course in a back water bay or up a tiny creek the charted depths might not be accurate , but usually its enough to at least run aground very slowly.

 

[Larry M]

FF wrote:

Today to NOT run aground all you need is your position.



Only if you have something to reference it to.* In Mexico and other counties we have been to, areas have not been re-surveyed since the original charts were made sometimes in the late 1800's and early 1900's.**The survey for Bahia de La Paz and the East Cape was done in 1897.* Puerto Morelos chart 28201 has its longitude off by +2 minutes, nearly 2 nm.* We rely on guidebooks and local knowledge. *Any hint or rumor of a reef and we stand clear several miles.

Larry/Lena
Hobo KK42
La Cruz, Nayarit, MX

 

[markpierce]

Sailor of Fortune wrote:

The difference between having the depth info at the bow as opposed to the stern is irrelevant
in my experience. Do you really think you would be able to stop and reverse your boats momentum in 35 feet or less?
If I am in a spot that requires that type of maneuver, I probably shouldn't be there in the first place.

In my contrary experiences in the San Francisco Bay/Delta area where there*are lots of shallow water and narrow to extremely-narrow channels, it is better to have the depth finder transducer mounted within the bow-half of the boat.

*

 

[hollywood8118]

As to where the transducer goes... I vote for the front half of the boat... BUT... we were backing down on the anchor in French Polynesia... up at the end of a deep bay, the rain water run off was so bad the water was dark brown. Dropped the hook in 50' of water... was backing down when ... you guessed it..... thud!. the rudder connects with a coral reef.. depth sounder still read 50'!. I used the boat hook and sure enough the damn reef was about 3' under water.* The Charted position was for the reef to be over 1/2 mile away.
no damage but to the skippers pride... this made future groundings less stressful.... and continues to this day
Have fun... go boating... don't worry... you will hit the bottom eventually
HOLLYWOOD

 

[markpierce]

Hollywood, maybe it would be best if we all graduated to 360-degree sonar.*