Fishfinder wires too short

[Franklin]

I just recieved my new Garmin fish finder. I want to glue it to the inside of the hull up as far forward as I can...hopefully under the anchor locker, but the wire isn't long enough. I thought about cutting it and extending it with regular marine wire but then started to worry about messing it up via interference or something like that. Thoughts? I want to start this project tonight when I get off work.

 

[Clark]

I suppose you have a good reason to have it that far forward; my advice would be to reconsider. Maybe just ahead of the keel?

 

[sailaway78]

I don't think

you can extend those, but not positive. Give Garmin tech support a call. They are very knowledgable and helpful.

 

[Franklin]

I just called them and there answer was a 10' extension cable for $35. I'd do that but I'm so impatient that it would drive me nuts waiting on a little part like that He says that any little resistance I add to the wires throws things off so it might work but there was a better chance I'd mess it up by splicing.

Seems I have to decide between putting it just in front of the keel or waiting for the extension. I wanted to put it as far forward so I will have time to stop before I hit what I see on the screen if I'm going very slow. If it's at the keel, due to delay time, what I see is what I already hit. Decisions decisions...

 

[Ross]

Re: I don't think

In my opinion 30 feet isn't going to be a major factor in whether or not you hit the bottom. I doubt that the gulf coast is very lumpy, say, like the coast of Maine, But I can't stop my boat in 100 feet and I use my depth sounder to help me stay out of shallow water. I must have 4.5 feet and I prefer 6 feet and so set my alarm. Whether I have 6 feet at the bow or the stern doesn't trouble me because I have not yet hit the bottom with 6 feet under my stern.

 

[Franklin]

It helps with the channels. After riding out Ike in Galveston, I left Offats Bayou. The channel out had all it's markers torn off the poles and with all the forks and Ys, I was a little confused as to what was what. I was watching the depth sounder but that's at the keel. It went from 9' to 4' in a matter of a few feet. Because of my wing keel, I have to heel the boat over about 70% (rail a foot under water) to break it loose. Told myself I'm not getting stuck anymore.

Later I will buy a forward looking sonar and replace the depth sounder thru-hull with it but I wanted to get the fish finder first and see how that did on the bow.

 

[Franklin]

Now if I was going 1.5 knots and could see say 5' in front of the bow, then I should be able to stop before running aground. There have been many times where I'm trying to sqeeze through something, like at an entrence of an anchorage and I miss it. That's what this is hopefulling going to help with.

Note, water here is sooooo brown you can't see anything in it.

 

[yodaboda]

Don't cut the wire

I've tried this before on my fishing boat. It worked, but not as good. I would get static on the screen, and when I was on the throttle, I would lose the whole bottom. I would get wandering pixels as well (dots on the screen). You really lose the sensitivity. I ended up buying a new cable, $100. Learned my lesson.
$35 now and a little time for delivery is better than $135 and a lot of time, if it doesn't work out.
I know its hard to, but be patient.

Good Luck

 

[Don S/V ILLusion]

In a DC circuit it's impedance, not resistance that effect the circuit and although the mfg is theoretically correct that any added impedance can effect the sounder, that happens regardless of how you choose to extend the wiring. The ONLY advantage their cable extension has is to preclude you from screwing up the splice.

Any cable of equivalent size will work as long as you ensure the connections are properly made. The best method is to solder the connections and also use a crimp connection to take any strain off the soldered connection.

Soldered connections in and of themselves are not an accepted practice on boats for the sole reason they are not structural and therefore prone to separate if not also crimped. If you do both, you are assured of a secure and electrically low impedance connection which will not effect the readings of the sounder.

 

[Benny]

Franklin, If you have not done so, first determine that your transducer can shoot through the hull of the boat. If the hull is porous the signal may not carry as it will not travel through air. The purpose of a depth meter is not to avoid an impending grounding. It is mostly used to verify a position on a chart, navigate in fog following a bottom contour, get a more precise reading when approaching shore or entering or leaving channels. Some use it to set the scope of the anchor line. For all practical purposes the transducer need not be placed at the bow. The majority of transducers are placed either on the starboard or port sides 12" or so away from center. Are you going to use epoxy which would require that it be in a somewhat leveled position or the old trusted method of a toilet wax ring?

 

[sailingdog]

Also, might want to be aware that if the transducer is too far forward, it may be in the turbulent water that will interfere with it functioning properly.

 

[Manny]

Benny has a good point, please test that it will shoot through the hull. I have a Garmin fishfinder. I also wanted it as far forward as possible and I spent a lot of time trying to get it to work through the hull but didn't have any success at all. I tried a wax toilet rings and bags of water in quite a few locations, no luck whatsoever.

Manny

 

[sailingdog]

Manny-

Do you have a cored hull? If so, that could be the issue. A transducer can't shoot through the hull unless it is a solid fiberglass section.

 

[Franklin]

Well, I tried to attach it to the hull just forward of the keel. I thought I had enough wire for that but it turned out I was two feet short, so I ordered the extension. I wasn't smart enough to test it before hand. Wish I thought of that sooner. Right now the wire is all ran under the liner and it was a pain so I'll wait until I get the extension and then test before I mount it. Was planning on attaching it to the hull with caulking.

 

[sailingdog]

Franklin-

If you're going to use caulking, don't use 5200. IMHO, if you're installing a through-the-hull transducer inside the boat, you should use the PVC pipe installation method. It is far more secure and allows for easy removal of the transducer for repair or upgrading.

 

[Timo42]

I am looking at the transducer for my new Garmin chartplotter:dance: now, the cable appears to be shielded twisted pair inside the insulation. If you do decide to lengthen it, standard wire wont work, it has to be the same type of wire and you need to shield the splice. I have done it with automotive speed sensor wiring, but it is a pita and in a marine environment... :cry: Tim

 

[captain cajun]

toilet wax ring, Please write more about the wax ring. I have been thinking about using my fish finder on my com-pac 16. What the best way to install it, please from start to finish. please.

thanks don

 

[knowitall]

Research the archives here re this topic.

Type in - "in hull transducer" and you will find all kinds of information on the proper installation of the transducer.
The manufacturers recommend using "slow cure" epoxy for the final set in place. Check their instructions.

 

[captain cajun]

Re: Research the archives here re this topic.

Thanks, so much

 

[knowitall]

dig - you're welcome. Lots of good info there eh?

With the site changes recently made here, many are not aware.