depth sounder

[Alfred Palma]

I just installed a Garmin 178c chart plotter with the depth sounder capacity.  The in hull sounder has approx 24' of cable.  Obviously I can't stretch this cable to the bow. Can I install in the rear opposite the engine intake and expect it to function reasonable well

[Joe Kern]

I don't know whether there would be a technical problem being near the engine intake, but I know that if you put it there your keel will notify you of the bottom before your depth sounder does.

I am sure you can get an extension/longer cable for the transducer. 

[Jim Price]

Check Garmin site for extension cables.  I am sure they have something. 

I have my transducer (not Garmin) forward under the V-Berth.  You want to place as far forward as possible so you can have a better idea of what is about to happen, not what just happened.

I know you only have a split second if something happens but setting the alarm will give you ample warning.  If your unit has plotting capability, then you will see the bottom rising before you hit (of course it helps if you are watching!!!!)

[Jon Schneider]

It's hard to argue with placing the sounder as far forward as possible, but, frankly, if you're sailing at 3+ kts and your forward-mounted sounder says you're about to hit something, do you really have time to avoid it?  If it's an object, you're going to hit it, and 10 extra feet of warning isn't going to change that.  But don't you already have a sounder (and the consequent hole)?  Are you adding this as a second sounder?  If not, why not use the current transponder?  If it's more than 24' away, then by all means get the extension, but if it's already nearby, why not just use that transponder (or at least, it's hole)?  BTW, my sounder transponder is slightly starboard of midship and just aft (about a 6") of the sink.  It wasn't my choice to put it there, but it works well.  I replaced the transponder when I upgraded all of the electronics to Raymarine ST-60s, and it was a bit of a PITA to reach... requiring some contortions.  In retrospect, I should have cut a hole in the floor (under the sole) for easy access.

[Ron Hill]

I believe that if you'd have checked with companies that make depth finders here's what they'd tell you on transducer placement in the hull.
1. Place in the flatest portion of the hull to eliminate the most paralax.
2. Place transducer in a location that is in "clean" water where there is NO or the least hull turbulence.

A thought.

[Jim Price]

I agree with Ron but failed to mention I have a "thru the glass" unit that sits level within the bow area and does not require an additional hole.  That is an important difference when considerding placement.

[Ken Heyman]

Just curious----Is it likely that a transducer from one manufacturer would be compatable with another mfg's unit(assuming the fittings are the same). I always thought that transducers were pretty much a "dedicated" piece of hardware. I know the mfgs. want you to believe that you can not mix and match

Ken.

[Pronto]

I am replacing a DataMarine thru-hull transponder with a Garmin in-hull which has a 5/8" limitation for hull thickness.  The old/current unit hides under the forward water tank to starboard and is virtually inaccessable.  How thick is the hull just forward of the keel?
Bob

[Dave Spencer]

Hi Pronto,
Welcome to the forum.  You'll find lots of help here.  I recall there being some info about hull thickness when others were talking about installing garboard drains.  Here is a link where the writer describes the hull being approx 1/2" thick near the mast step. (sounds fairly thin to me) 
http://c34.org/bbs/index.php/topic,6412.0.html
This may or may not be representative of the area you're thinking about.  At least you don't have to drill a hole to find out if the transducer will work or not!

Good luck with your transducer installation.

[Ron Hill]

Pronto : If the present transducer is in a nearly inaccessible Vberth location in the hull, think about changing the location.
You could leave the old transducer to plug the hole is you don't want to fiberglass over it.  I'd fiberglass over the old hole.

My transducers for the depth finder and the knot log are in the hull under the seat just forward of the mast.  Easy to get to. 

A few thoughts

[2ndwish]

Ken's comment is right on. The Garmin unit uses 200KHz or 50 KHz transducers. It is possibly compatible with what is already there, but without knowing what unit is installed, it is hard to say for sure. Datamarine used 120KHz and 200 KHz. Do a little web-based homework and you may save yourself trouble and expense. Last year our venerable  old Signet depth sounder readout unit bit the dust. I happened to have an ST-60 which was a near drop-in replacement using the same transducer. The wiring was very simple and is detailed on mainesail's web page. While it is described as a temporary fix, I couldn't see a reason to change it.

http://www.pbase.com/mainecruising/new_depth_old_transducer_ducer

While you're there buy some butyl tape!

[Ron Hill]

Pronto : It may be too late, but you can get Datamarine instruments repaired by calling DMI at
(508 564-7491

A thought

[RobertSchuldenfrei]

We have two depth sounders, one on a Garmin 178C chartplotter, and an inexpensive backup Hawkeye.  The transducers are forward, one under the V berth and the other just inside the main cabin.  They operate on different frequencies so they do not interfere.  Both instruments are in-hull and cable length is not a problem.  We got the Hawkeye when we were having "issues" with the Garmin.  When the Garmin got fixed, it is nice to have a backup.  Both give almost the same depth all of the time.  Notice that our new instrument fit into the original "pods."  Since we get our speed on the GPS, the port pod holds our API.

Cheers,

Bob

PS:  I just noticed that this thread was started by Al Palma, the previous owner of Catalina 34 #422.  "What goes around, comes around."

[Tom Soko]

Bob,
I noticed in your pic that you still have the plastic shift and throttle handles.  You might want to consider changing them to the SS models.  It's not a question of if they will break, but a question of when.....and it's NEVER at a good time.  Just a thought.

[RobertSchuldenfrei]

Bob,
I noticed in your pic that you still have the plastic shift and throttle handles.  You might want to consider changing them to the SS models.  It's not a question of if they will break, but a question of when.....and it's NEVER at a good time.  Just a thought.

Hi Tom,

Thanks for the tip.  It has been on my "to-do" list and I will now move it up to top priority.  I keep a vice-grip pliers near by  .  Where can I get the SS replacements?  OK, skip the question; the answer was in this forum:  MarinePartDepot.com. 

Cheers,

Bob